[1.0.x] Fixed #8803 -- Allow authenticated users without first_name/last_name...

[1.0.x] Fixed #8803 -- Allow authenticated users without first_name/last_name values set to post comments.

Backport of r9118 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9125 bcc190cf-cafb-0310-a4f2-bffc1f526a37