mark all dtors which are virtual because base class dtor is virtual explicitly virtual themselves

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41020 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/paletteg.cpp

@@ -33,7 +33,7 @@ class wxPaletteRefData: public wxObjectRefData
   public:
 
     wxPaletteRefData(void);
-    ~wxPaletteRefData(void);
+    virtual ~wxPaletteRefData(void);
 
     int m_count;
     wxPaletteEntry *m_entries;