Fixed #10997: fixed a Python 2.4-ism in admin actions.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10705 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/actions.py

@@ -12,6 +12,10 @@ from django.utils.html import escape
 from django.utils.safestring import mark_safe
 from django.utils.text import capfirst
 from django.utils.translation import ugettext_lazy, ugettext as _
+try:
+    set
+except NameError:
+    from sets import Set as set     # Python 2.3 fallback
 
 def delete_selected(modeladmin, request, queryset):
     """