Fixed #12892 - Fixed unicode related bug in a utility function of the...

Fixed #12892 - Fixed unicode related bug in a utility function of the admindocs app that prevented it to be used in non-English environments together with certain versions of docutils.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13192 bcc190cf-cafb-0310-a4f2-bffc1f526a37