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/x11/dcclient.h

@@ -35,7 +35,7 @@ public:
     wxWindowDC();
     wxWindowDC( wxWindow *win );
 
-    ~wxWindowDC();
+    virtual ~wxWindowDC();
 
     virtual bool CanDrawBitmap() const { return true; }
     virtual bool CanGetTextExtent() const { return true; }