[gtk+] docs: Remove vfunc that doesn't exist anymore

[Benjamin Otte <otte src gnome org>]

commit a178258a2a55fc51479aa5f6cff745c79283ec48
Author: Benjamin Otte <otte redhat com>
Date:   Thu Nov 3 05:32:37 2016 +0100

    docs: Remove vfunc that doesn't exist anymore

 gtk/gtkwidget.h |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkwidget.h b/gtk/gtkwidget.h
index e3adad3..f81b4eb 100644
--- a/gtk/gtkwidget.h
+++ b/gtk/gtkwidget.h
@@ -237,8 +237,6 @@ struct _GtkWidget
  * @selection_notify_event:
  * @proximity_in_event:
  * @proximity_out_event:
- * @visibility_notify_event: Signal emitted when the widget’s window is
- *   obscured or unobscured.
  * @window_state_event: Signal emitted when the state of the toplevel
  *   window associated to the widget changes.
  * @grab_broken_event: Signal emitted when a pointer or keyboard grab