fixed delete undo.

src/widgets/xqtreetable.h

@@ -38,7 +38,7 @@ public:
   XQTreeTable(QWidget* parent = nullptr );
   virtual ~XQTreeTable() = default;
 
-  XQViewModel* modelView();
+  XQViewModel* viewModel();
   XQItem&  xqItemFromIndex(const QModelIndex& index );
 
   void toggleRowsHidden(int fstRow, int lstRow );