[pitivi] previewers: Optimize thumbnails reuse

[Mathieu Duponchelle <mathieudu src gnome org>]

commit c9616fcfe23bf4fcdd232f1d8de7ad0b2a6beb0f
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Sun Dec 8 09:29:27 2013 +0100

    previewers: Optimize thumbnails reuse

 pitivi/timeline/previewers.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/timeline/previewers.py b/pitivi/timeline/previewers.py
index f2f0799..2f531ac 100644
--- a/pitivi/timeline/previewers.py
+++ b/pitivi/timeline/previewers.py
@@ -337,7 +337,7 @@ class VideoPreviewer(Clutter.ScrollActor, PreviewGenerator, Zoomable, Loggable):
         Get the thumbnails to be displayed in the currently visible clip portion
         """
         self.remove_all_children()
-        old_thumbs = self.thumbs.copy()
+        old_thumbs = self.thumbs
         self.thumbs = {}
         self.wishlist = []