Add workaround for delegate stuck transition bug

Sometimes and randomly, a HListView/HGridView delegate's
add/populate transition will stop before completion.

This especially happens on startup when loading a large room list,
one room might get stuck and left tiny or invisible, despite its
normal space still being taken.

src/gui/Pages/AddAccount/ServerDelegate.qml

@@ -92,4 +92,6 @@ HTile {
     }
 
     Behavior on contentOpacity { HNumberAnimation {} }
+
+    DelegateTransitionFixer {}
 }