QmlDesigner.NodeInstances: Use windowTransform instead of canvasTransform

Change-Id: I157c5346bbc69a10166a74df5a5a4f8bdfadd9fd
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/sgitemnodeinstance.cpp

@@ -143,8 +143,7 @@ QTransform QuickItemNodeInstance::customTransform() const
 
 QTransform QuickItemNodeInstance::sceneTransform() const
 {
-    return QTransform();
-//    return DesignerSupport::canvasTransform(quickItem());
+    return DesignerSupport::windowTransform(quickItem());
 }
 
 double QuickItemNodeInstance::rotation() const