[gtk] gtkmain: Remove comment mentioning GDK_PROPERTY_NOTIFY

[Timm Bäder <baedert src gnome org>]

commit 0a5362a7d94c53bafe2d9dd8f71c5f8d99bb31ce
Author: Timm Bäder <mail baedert org>
Date:   Tue Jan 29 05:29:57 2019 +0100

    gtkmain: Remove comment mentioning GDK_PROPERTY_NOTIFY
    
    ... which doesn't exist anymore.

 gtk/gtkmain.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/gtk/gtkmain.c b/gtk/gtkmain.c
index 8222f5774b..db05822cf5 100644
--- a/gtk/gtkmain.c
+++ b/gtk/gtkmain.c
@@ -1728,9 +1728,7 @@ gtk_main_do_event (GdkEvent *event)
 
   /* Find the widget which got the event. We store the widget
    * in the user_data field of GdkSurface's. Ignore the event
-   * if we don't have a widget for it, except for GDK_PROPERTY_NOTIFY
-   * events which are handled specially. Though this happens rarely,
-   * bogus events can occur for e.g. destroyed GdkSurfaces.
+   * if we don't have a widget for it.
    */
   event_widget = gtk_get_event_widget (event);
   if (!event_widget)