return size without decorations from size_request GTK callback in wxTLW

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44508 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/window.cpp

@@ -2556,7 +2556,7 @@ void wxWindowGTK::PostCreation()
         // FIXME: what should be done here ?
     }
 #endif
-    else
+    else if ( !IsTopLevel() ) // top level windows use their own callback
     {
         // This is needed if we want to add our windows into native
         // GTK controls, such as the toolbar. With this callback, the