Merge pull request #285 from github/fixes/242-validation-adornment

Keep validation adornment visibility up to date

Author: shana

src/GitHub.UI.Reactive/Controls/Validation/ValidationMessage.cs

@@ -33,6 +33,7 @@ public ValidationMessage()
                 .Do(CreateBinding)
                 .Select(control =>
                     Observable.Merge(
+                        this.WhenAnyValue(x => x.ShowError),
                         control.Events().TextChanged
                             .Throttle(TimeSpan.FromSeconds(ShowError ? defaultTextChangeThrottle : TextChangeThrottle),
                             RxApp.MainThreadScheduler)