QmlDesigner: unused private header

Change-Id: Ife75552afb9d96ac760b0d37f0dbd772a35c498c
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

src/plugins/qmldesigner/designercore/instances/nodeinstanceview.cpp

@@ -32,7 +32,6 @@
 
 #include <QDeclarativeEngine>
 #include <QDeclarativeContext>
-#include <private/qdeclarativeengine_p.h>
 
 #include <QUrl>
 #include <QGraphicsView>