[gtk/ebassi/unexport-x11] Remove unnecessary warning

[Emmanuele Bassi <ebassi src gnome org>]

commit 226f0e05679aa2fd0425d29c98ab2ef30d4e96b9
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Feb 24 02:04:06 2022 +0000

    Remove unnecessary warning
    
    Unexporting the window handle on X11 is a no-op, so there's no need
    to emit a warning.

 gtk/gtkwindow.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index d9856d8b5e..9c58c36f1b 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -6324,6 +6324,10 @@ gtk_window_unexport_handle (GtkWindow *window)
       return;
     }
 #endif
+#ifdef GDK_WINDOWING_X11
+  if (GDK_IS_X11_DISPLAY (gtk_widget_get_display (GTK_WIDGET (window))))
+    return;
+#endif
 
   g_warning ("Couldn't unexport handle for %s surface, unsupported windowing system",
              G_OBJECT_TYPE_NAME (priv->surface));