More warning fixes

osu.Desktop/Overlays/VersionManager.cs

@@ -233,7 +233,8 @@ namespace osu.Desktop.Overlays
                 Text = @"Update ready to install. Click to restart!",
                 Activated = () =>
                 {
-                    UpdateManager.RestartAppWhenExited();
+                    // Squirrel returns execution to us after the update process is started, so it's safe to use Wait() here
+                    UpdateManager.RestartAppWhenExited().Wait();
                     game.GracefullyExit();
                     return true;
                 }