don't use deprecated wxIconizeEvent::Iconized()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54348 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/mdi.cpp

@@ -344,11 +344,9 @@ void wxMDIParentFrame::OnIconized(wxIconizeEvent& event)
 {
     event.Skip();
 
-    if ( !event.Iconized() )
-    {
+    if ( !event.IsIconized() )
         UpdateClientSize();
 }
-}
 
 // Returns the active MDI child window
 wxMDIChildFrame *wxMDIParentFrame::GetActiveChild() const