Cast for argument to delete[] - VC6 doesn't want to delete a const pointer

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@53619 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/app.cpp

@@ -471,7 +471,7 @@ static bool UnregisterAndFreeClassName(const wxChar **ppClassName)
         retval = false;
     }
 
-    delete [] *ppClassName;
+    delete [] (wxChar*) *ppClassName;
     *ppClassName = NULL;
 
     return retval;