Include wx/intl.h according to precompiled headers of wx/wx.h (with other minor cleaning).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38909 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/mdi.cpp

@@ -10,14 +10,17 @@
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
-#include "wx/mdi.h"
-#include "wx/notebook.h"
-
 #if wxUSE_MDI
 
+#include "wx/mdi.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/intl.h"
+#endif
+
+#include "wx/notebook.h"
 #include "wx/dialog.h"
 #include "wx/menu.h"
-#include "wx/intl.h"
 #include "wx/gtk/private.h"
 
 #include <glib.h>