BUG: Fixed Monteverdi compilation error

Modules/Visualization/MonteverdiCore/include/mvdStackedLayerModel.h

@@ -295,8 +295,6 @@ private:
 
   LayerModelMap m_LayerModels;
   KeyVector     m_Keys;
-  SizeType      m_Current{0,0};
-  SizeType      m_Reference{0,0};
 
   // Usually, information is a singular term which denotes a
   // plural. Since there's a container of several pixel-infos and we