[pitivi] ruler: set callback_id_scroll to None when callback occured.

[Mathieu Duponchelle <mathieudu src gnome org>]

commit 4edd145c88576e20fea6f7c5e37451361c3a198b
Author: Mathieu Duponchelle <mduponchelle1 gmail com>
Date:   Fri Jan 17 00:31:21 2014 +0100

    ruler: set callback_id_scroll to None when callback occured.

 pitivi/timeline/ruler.py |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/timeline/ruler.py b/pitivi/timeline/ruler.py
index 2d96743..b60525e 100644
--- a/pitivi/timeline/ruler.py
+++ b/pitivi/timeline/ruler.py
@@ -124,6 +124,7 @@ class ScaleRuler(Gtk.DrawingArea, Zoomable, Loggable):
     def _maybeUpdate(self):
         self.queue_draw()
         self.callback_id = None
+        self.callback_id_scroll = None
         return False
 
     def zoomChanged(self):