Fixed #12965 - unordered_list template filter fails when given a non-iterable...

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.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13845 bcc190cf-cafb-0310-a4f2-bffc1f526a37