applied workaround patch to get rid of crashes in wxrcedit on MSW

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10285 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

contrib/utils/wxrcedit/preview.h

@@ -57,6 +57,9 @@ class PreviewFrame : public wxFrame
         
         DECLARE_EVENT_TABLE()
         void OnMouseEnter(wxMouseEvent& event);
+#ifdef __WXMSW__
+        void OnActivate(wxActivateEvent &event);
+#endif
 };