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/generic/colour.h

@@ -30,7 +30,7 @@ public:
     wxColour& operator=(const wxColour& col);
 
     // dtor
-    ~wxColour();
+    virtual ~wxColour();
 
     // accessors
     bool Ok() const { return m_isInit; }