[1.2.X] Fixed #12965 - unordered_list template filter fails when given a...

[1.2.X] Fixed #12965 - unordered_list template filter fails when given a non-iterable second item in a two item list

Thanks to grahamu for the report and patch.

Backport of [13845] from trunk

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13846 bcc190cf-cafb-0310-a4f2-bffc1f526a37