[applet/contents/ui/ConnectionItem] Fix trying to reach non existing objects

applet/contents/ui/ConnectionItem.qml

@@ -309,6 +309,8 @@ PlasmaExtras.ExpandableListItem {
     }
 
     Component.onDestruction: {
-        full.connectionModel.delayModelUpdates = false;
+        if ( full != null && full.connectionModel != null) {
+            full.connectionModel.delayModelUpdates = false;
+        }
     }
 }