Backport #653 into 2.1.0

src/GitHub.App/ViewModels/PullRequestListViewModel.cs

@@ -108,6 +108,11 @@ public override void Initialize([AllowNull] ViewWithData data)
 
             pullRequests.OriginalCompleted
                 .ObserveOn(RxApp.MainThreadScheduler)
+                .Catch<System.Reactive.Unit, Octokit.AuthorizationException>(ex =>
+                {
+                    // TODO: Do some decent logging here
+                    return repositoryHost.LogOut();
+                })
                 .Subscribe(_ =>
                 {
                     if (listSettings.SelectedAuthor != null)