Fix a bug that caused some NotificationViews to be double-shown.

This bug affected views added while the window was hidden, and would
result in that view not being hidden when the group was collapsed for
the first time.

src/servers/notification/AppGroupView.cpp

@@ -206,7 +206,7 @@ AppGroupView::AddInfo(NotificationView* view)
 
 	if (IsHidden())
 		Show();
-	if (view->IsHidden() && !fCollapsed)
+	if (view->IsHidden(view) && !fCollapsed)
 		view->Show();
 }