[extensions-web] Diff against the previous version, not the latest version

[Jasper St. Pierre <jstpierre src gnome org>]

commit 7891187e583377fcc378d40bbb1a6a0ade97710d
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Nov 22 18:09:17 2011 -0500

    Diff against the previous version, not the latest version

 sweettooth/review/views.py |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/sweettooth/review/views.py b/sweettooth/review/views.py
index 2b62cbc..4a5af66 100644
--- a/sweettooth/review/views.py
+++ b/sweettooth/review/views.py
@@ -108,11 +108,11 @@ def get_zipfiles(version):
     extension = version.extension
 
     new_zipfile = version.get_zipfile('r')
-
-    if extension.latest_version is None:
+    if version.version == 1:
         return None, new_zipfile
 
-    old_zipfile = extension.latest_version.get_zipfile('r')
+    old_version = extension.versions.get(version=version.version-1)
+    old_zipfile = old_version.get_zipfile('r')
 
     return old_zipfile, new_zipfile