Avoid error message when closing message

dialog with the X field from the WM.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30801 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk1/msgdlg.h

@@ -31,6 +31,7 @@ public:
                     const wxString& caption = wxMessageBoxCaptionStr,
                     long style = wxOK|wxCENTRE,
                     const wxPoint& pos = wxDefaultPosition);
+    ~wxMessageDialog();
 
     int ShowModal();
     virtual bool Show( bool WXUNUSED(show) = true ) { return false; };