make GetPaperRect() and GetResolution() const functions

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56783 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/print.h

@@ -249,10 +249,10 @@ public:
     void SetBackgroundMode(int mode);
     void SetPalette(const wxPalette& WXUNUSED(palette)) { }
     void SetResolution(int ppi);
-    
+
     // overriden for wxPrinterDC Impl
-    virtual int GetResolution();
-    virtual wxRect GetPaperRect();
+    virtual int GetResolution() const;
+    virtual wxRect GetPaperRect() const;
 
 protected:
     bool DoFloodFill(wxCoord x1, wxCoord y1, const wxColour &col, int style=wxFLOOD_SURFACE );