[gtk+] window: Remove GtkButton reference from docs

[Matthias Clasen <matthiasc src gnome org>]

commit 371d5270928cea929219496cdf515b507342fc65
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Dec 26 14:06:17 2017 -0500

    window: Remove GtkButton reference from docs
    
    GtkButton doesn't have its own window anymore, so it is
    a misleading example here.

 gdk/gdkwindow.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 9a10fce..c553a26 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -64,8 +64,7 @@
  * It’s a low-level object, used to implement high-level objects such as
  * #GtkWidget and #GtkWindow on the GTK+ level. A #GtkWindow is a toplevel
  * window, the thing a user might think of as a “window” with a titlebar
- * and so on; a #GtkWindow may contain many #GdkWindows. For example,
- * each #GtkButton has a #GdkWindow associated with it.
+ * and so on; a #GtkWindow may contain many sub-GdkWindows.
  */
 
 /**