Fixed #5636 -- Added missing Set import for Python2.3 support. Thanks, wangchun@exoweb.net.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6438 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/auth/backends.py

@@ -1,6 +1,11 @@
 from django.db import connection
 from django.contrib.auth.models import User
 
+try: 
+    set 
+except NameError: 
+    from sets import Set as set # Python 2.3 fallback
+ 	
 class ModelBackend:
     """
     Authenticate against django.contrib.auth.models.User