Fix server build on Ubuntu 20.04 and 22.04

[Quipyowert2]

This fixes the linker error when building the server on Ubuntu 20.04 in #77.

The second commit fixes the packaging error during the Ubuntu 22.04 CI build for PR #77. The oldest Ubuntu version specified in either that PR or in .travis.yml is 16.04 which has version 9 of debhelper. Ubuntu 22.04 build in PR #77 fails because debhelper 13 isn't backward compatible with version 6. The packaging guide for debian recommends using version 10 but says compatibility level 9 can be used for builds on older systems.

In case the build log expires, the last several lines of the build log are:

Build log from Ubuntu 20.04 in GitHub actions

 g++ -o build/src/YOGServerRouterAdministratorCommands.o -c -g -Wall -fPIC -DYOG_SERVER_ONLY -DHAVE_CONFIG_H -D_REENTRANT -Ilibgag/include -I. -Ilibusl/src -I/usr/include/SDL2 src/YOGServerRouterAdministratorCommands.cpp
g++ -o build/src/YOGServerRouterAdministrator.o -c -g -Wall -fPIC -DYOG_SERVER_ONLY -DHAVE_CONFIG_H -D_REENTRANT -Ilibgag/include -I. -Ilibusl/src -I/usr/include/SDL2 src/YOGServerRouterAdministrator.cpp
g++ -o build/src/YOGServerRouter.o -c -g -Wall -fPIC -DYOG_SERVER_ONLY -DHAVE_CONFIG_H -D_REENTRANT -Ilibgag/include -I. -Ilibusl/src -I/usr/include/SDL2 src/YOGServerRouter.cpp
g++ -o build/src/YOGServerRouterManager.o -c -g -Wall -fPIC -DYOG_SERVER_ONLY -DHAVE_CONFIG_H -D_REENTRANT -Ilibgag/include -I. -Ilibusl/src -I/usr/include/SDL2 src/YOGServerRouterManager.cpp
g++ -o build/src/YOGServerRouterPlayer.o -c -g -Wall -fPIC -DYOG_SERVER_ONLY -DHAVE_CONFIG_H -D_REENTRANT -Ilibgag/include -I. -Ilibusl/src -I/usr/include/SDL2 src/YOGServerRouterPlayer.cpp
g++ -o build/src/glob2-server -g -Wall build/src/AINames.o build/src/BasePlayer.o build/src/BaseTeam.o build/src/BitArray.o build/src/GameHeader.o build/src/LANGameInformation.o build/src/LogFileManager.o build/src/MapHeader.o build/src/NetBroadcaster.o build/src/NetConnection.o build/src/NetConnectionThread.o build/src/NetConnectionThreadMessage.o build/src/NetGamePlayerManager.o build/src/NetListener.o build/src/NetMessage.o build/src/NetReteamingInformation.o build/src/NetTestSuite.o build/src/Order.o build/src/Race.o build/src/UnitType.o build/src/Utilities.o build/src/YOGConsts.o build/src/YOGGameInfo.o build/src/YOGGameResults.o build/src/YOGMessage.o build/src/YOGPlayerSessionInfo.o build/src/YOGPlayerStoredInfo.o build/src/BuildingUtils.o build/src/Bullet.o build/src/EntityType.o build/src/Glob2.o build/src/GlobalContainer.o build/src/Map.o build/src/MapThumbnail.o build/src/Sector.o build/src/Settings.o build/src/UnitUtils.o build/src/YOGAfterJoinGameInformation.o build/src/YOGDownloadableMapInfo.o build/src/WinningConditions.o build/src/YOGServerAdministratorCommands.o build/src/YOGServerAdministrator.o build/src/YOGServerAdministratorList.o build/src/YOGServerBannedIPListManager.o build/src/YOGServerChatChannel.o build/src/YOGServerChatChannelManager.o build/src/YOGServer.o build/src/YOGServerFileDistributationManager.o build/src/YOGServerFileDistributor.o build/src/YOGServerGame.o build/src/YOGServerGameLog.o build/src/YOGServerGameRouter.o build/src/YOGServerMapDatabank.o build/src/YOGServerPasswordRegistry.o build/src/YOGServerPlayer.o build/src/YOGServerPlayerScoreCalculator.o build/src/YOGServerPlayerStoredInfoManager.o build/src/YOGServerRouterAdministratorCommands.o build/src/YOGServerRouterAdministrator.o build/src/YOGServerRouter.o build/src/YOGServerRouterManager.o build/src/YOGServerRouterPlayer.o build/libgag/src/libgag_server.a -lz -lboost_thread -lboost_system -lpthread -lSDL2_net -lSDL2
/bin/ld: build/src/Settings.o: in function `Settings::load(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
/home/runner/work/glob2/glob2/src/Settings.cpp:129: undefined reference to `GAGGUI::Screen::scrollWheelEnabled'
collect2: error: ld returned 1 exit status
scons: *** [build/src/glob2-server] Error 1
scons: building terminated because of errors.
make: *** [debian/rules:32: build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2
Error: Process completed with exit code 2.

and the 22.04 build log end with:

Build log from Ubuntu 22.04 in GitHub actions

g++ -o build/src/glob2 -g -Wall build/src/AICastor.o build/src/AI.o build/src/AIDescriptionScreen.o build/src/AIEcho.o build/src/AINames.o build/src/AINicowar.o build/src/AINull.o build/src/AINumbi.o build/src/AIToubib.o build/src/AIWarrush.o build/src/BasePlayer.o build/src/BaseTeam.o build/src/BitArray.o build/src/Brush.o build/src/Building.o build/src/BuildingsTypes.o build/src/BuildingType.o build/src/BuildingUtils.o build/src/Bullet.o build/src/Campaign.o build/src/CampaignEditor.o build/src/CampaignMainMenu.o build/src/CampaignMenuScreen.o build/src/CampaignSelectorScreen.o build/src/ChooseMapScreen.o build/src/CPUStatisticsManager.o build/src/CreditScreen.o build/src/CustomGameOtherOptions.o build/src/CustomGameScreen.o build/src/DynamicClouds.o build/src/EditorMainMenu.o build/src/EndGameScreen.o build/src/Engine.o build/src/EntityType.o build/src/Fatal.o build/src/FertilityCalculatorDialog.o build/src/FertilityCalculatorThread.o build/src/FertilityCalculatorThreadMessage.o build/src/Game.o build/src/GameEvent.o build/src/GameGUI.o build/src/GameGUIDefaultAssignManager.o build/src/GameGUIDialog.o build/src/GameGUIGhostBuildingManager.o build/src/GameGUIKeyActions.o build/src/GameGUILoadSave.o build/src/GameGUIMessageManager.o build/src/GameGUIToolManager.o build/src/GameHeader.o build/src/GameHints.o build/src/GameObjectives.o build/src/GameUtilities.o build/src/Glob2.o build/src/Glob2Screen.o build/src/Glob2Style.o build/src/GlobalContainer.o build/src/Gradient.o build/src/GUIGlob2FileList.o build/src/GUIMapPreview.o build/src/HeightMapGenerator.o build/src/IntBuildingType.o build/src/IRC.o build/src/IRCTextMessageHandler.o build/src/IRCThread.o build/src/IRCThreadMessage.o build/src/KeyboardManager.o build/src/LANFindScreen.o build/src/LANGameInformation.o build/src/LANMenuScreen.o build/src/LogFileManager.o build/src/MainMenuScreen.o build/src/Map.o build/src/MapEdit.o build/src/MapEditDialog.o build/src/MapEditKeyActions.o build/src/MapGenerationDescriptor.o build/src/MapGenerator.o build/src/MapHeader.o build/src/MapScript.o build/src/MapScriptError.o build/src/MapScriptUSL.o build/src/MapThumbnail.o build/src/MarkManager.o build/src/Minimap.o build/src/MultiplayerGame.o build/src/MultiplayerGameEvent.o build/src/MultiplayerGameEventListener.o build/src/MultiplayerGameScreen.o build/src/NetBroadcaster.o build/src/NetBroadcastListener.o build/src/NetConnection.o build/src/NetConnectionThread.o build/src/NetConnectionThreadMessage.o build/src/NetEngine.o build/src/NetGamePlayerManager.o build/src/NetListener.o build/src/NetMessage.o build/src/NetReteamingInformation.o build/src/NetTestSuite.o build/src/NewMapScreen.o build/src/Order.o build/src/OverlayAreas.o build/src/PerlinNoise.o build/src/Player.o build/src/Race.o build/src/ReplayReader.o build/src/ReplayWriter.o build/src/Ressource.o build/src/RessourcesTypes.o build/src/ScriptEditorScreen.o build/src/Sector.o build/src/Settings.o build/src/SettingsScreen.o build/src/SGSL.o build/src/SimplexNoise.o build/src/SoundMixer.o build/src/Team.o build/src/TeamStat.o build/src/UnitConsts.o build/src/Unit.o build/src/UnitEditorScreen.o build/src/UnitSkin.o build/src/UnitsSkins.o build/src/UnitType.o build/src/UnitUtils.o build/src/Utilities.o build/src/VoiceRecorder.o build/src/WinningConditions.o build/src/YOGAfterJoinGameInformation.o build/src/YOGClientBlockedList.o build/src/YOGClientChatChannel.o build/src/YOGClientChatListener.o build/src/YOGClientCommandManager.o build/src/YOGClientCommands.o build/src/YOGClient.o build/src/YOGClientDownloadableMapList.o build/src/YOGClientDownloadableMapListener.o build/src/YOGClientDownloadingMapScreen.o build/src/YOGClientEvent.o build/src/YOGClientEventListener.o build/src/YOGClientFileAssembler.o build/src/YOGClientGameConnectionDialog.o build/src/YOGClientGameListListener.o build/src/YOGClientGameListManager.o build/src/YOGClientLobbyScreen.o build/src/YOGClientMapDownloader.o build/src/YOGClientMapDownloadScreen.o build/src/YOGClientMapUploader.o build/src/YOGClientMapUploadScreen.o build/src/YOGClientOptionsScreen.o build/src/YOGClientPlayerListListener.o build/src/YOGClientPlayerListManager.o build/src/YOGClientRatedMapList.o build/src/YOGClientRouterAdministrator.o build/src/YOGConsts.o build/src/YOGDownloadableMapInfo.o build/src/YOGGameInfo.o build/src/YOGGameResults.o build/src/YOGLoginScreen.o build/src/YOGMessage.o build/src/YOGPlayerPrivateInfo.o build/src/YOGPlayerSessionInfo.o build/src/YOGPlayerStoredInfo.o build/src/YOGRegisterScreen.o build/src/YOGServerAdministratorCommands.o build/src/YOGServerAdministrator.o build/src/YOGServerAdministratorList.o build/src/YOGServerBannedIPListManager.o build/src/YOGServerChatChannel.o build/src/YOGServerChatChannelManager.o build/src/YOGServer.o build/src/YOGServerFileDistributationManager.o build/src/YOGServerFileDistributor.o build/src/YOGServerGame.o build/src/YOGServerGameLog.o build/src/YOGServerGameRouter.o build/src/YOGServerMapDatabank.o build/src/YOGServerPasswordRegistry.o build/src/YOGServerPlayer.o build/src/YOGServerPlayerScoreCalculator.o build/src/YOGServerPlayerStoredInfoManager.o build/src/YOGServerRouterAdministratorCommands.o build/src/YOGServerRouterAdministrator.o build/src/YOGServerRouter.o build/src/YOGServerRouterManager.o build/src/YOGServerRouterPlayer.o build/libgag/src/libgag.a build/libusl/src/libusl.a -lz -lboost_thread -lboost_system -lpthread -lGL -lGLU -lfribidi -lSDL2_net -lvorbisfile -lSDL2_ttf -lSDL2_image -lspeex -lSDL2
scons: done building targets.
dpkg-buildpackage: info: source package glob2
dpkg-buildpackage: info: source version 0.9.5.0
dpkg-buildpackage: info: source distribution unstable
dpkg-buildpackage: info: source changed by Nikolay Epifanov <nick.time at yahoo dot com>
 dpkg-source -I.hg --before-build .
dpkg-buildpackage: info: host architecture amd64
 fakeroot debian/rules clean
QUILT_PATCHES=debian/patches \
	quilt --quiltrc /dev/null pop -a -R || test $? = 2
No patch removed
rm -rf .pc debian/stamp-patched
dh_testdir
dh_testroot
rm -f build-stamp
dh_clean
dh_clean: error: Compatibility levels before 7 are no longer supported (level 6 requested)
make: *** [debian/rules:45: clean] Error 25
dpkg-buildpackage: error: fakeroot debian/rules clean subprocess returned exit status 2
Error: Process completed with exit code 2.