QmlDesigner: fix a crash when moving to subcomponent

Change-Id: Ib8fd13a3688447dcb7eeaca811f3abfefa4b5089
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

src/plugins/qmldesigner/components/formeditor/selectiontool.cpp

@@ -251,6 +251,7 @@ void SelectionTool::clear()
     m_resizeIndicator.clear();
     m_anchorIndicator.clear();
     m_bindingIndicator.clear();
+    m_contentNotEditableIndicator.clear();
 
     AbstractFormEditorTool::clear();
 }