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

include/wx/gtk1/glcanvas.h

@@ -66,7 +66,7 @@ public:
                const wxPalette& WXUNUSED(palette),
                const wxGLContext *other        /* for sharing display lists */
     );
-    ~wxGLContext();
+    virtual ~wxGLContext();
 
     void SetCurrent();
     void SetColour(const wxChar *colour);
@@ -138,7 +138,7 @@ public:
                 int *attribList = (int*) NULL,
                 const wxPalette& palette = wxNullPalette );
 
-   ~wxGLCanvas();
+   virtual ~wxGLCanvas();
 
    void SetCurrent();
    void SetColour(const wxChar *colour);