Packages often did not able to refresh

[danielchim]

Problem

Sometimes when select a new game to manage, the online package list will keeps on showing empty list, despite the packages was being fetched on background. By design, the package will stales for 5 minutes and after 5 mins, the whole list will re-fetch again.

Steps to re-produce:

• Add a game to manage from the select game dialog
• Select a game and set the correct game path
• After adding a game to the manage list, the "online" tab will keeps no showing "no packages found"
• When restart the mod manager, the package list will show up properly.

Expected behavior

• Online packages will show up once the fetching is complete.

A related issue is on #13, @AkaraChen you may need to check both issues as they might point to the UI did not subscribe to the DB schema after the DB architecture update.