Settings page do not support touch screen scrolling

[lovelyelfpop]

Touch scrolling is not supported on touchscreen displays/monitors, nor is it supported when remotely connecting to a Windows PC using the Microsoft Remote Desktop app on Android.

[chrisuthe]

Fix submitted in PR #12 — adds PanningMode="VerticalOnly" to the ScrollViewer style. This enables touch scrolling on both the settings page and the welcome/server list view, including via Remote Desktop touch input.