[pitivi] Fix a bug in timeline edges that I added in c585ee

[Edward Hervey <edwardrv src gnome org>]

commit b58ee9ecc7532e47be05490987e7dfed65eb8112
Author: Alessandro Decina <alessandro d gmail com>
Date:   Tue Jul 14 10:54:58 2009 +0200

    Fix a bug in timeline edges that I added in c585ee

 pitivi/timeline/timeline.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index e37c3fb..b33be17 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -719,7 +719,7 @@ class TimelineEdges(object):
 
     def removeTrackObject(self, track_object):
         try:
-            old_start, old_end = self.by_object[track_object]
+            old_start, old_end = self.by_object.pop(track_object)
         except KeyError:
             raise TimelineError()