No real changes, just make wxDataViewCtrlInternal::IsSorted() const.

This is a simple accessor, should have been const since the beginning.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71326 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/dataview.cpp

@@ -268,7 +268,7 @@ public:
     void SetDataViewSortColumn( wxDataViewColumn *column ) { m_dataview_sort_column = column; }
     wxDataViewColumn *GetDataViewSortColumn()   { return m_dataview_sort_column; }
 
-    bool IsSorted()                             { return (m_sort_column >= 0); }
+    bool IsSorted() const                       { return m_sort_column >= 0; }
 
     // accessors
     wxDataViewModel* GetDataViewModel() { return m_wx_model; }