Fixed #14928 -- Ensure that a fully qualified domain name can be used for runserver. Thanks to Karmel Allison for the report, Łukasz Rekucki for the patch, and claudep for the tests.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15215 bcc190cf-cafb-0310-a4f2-bffc1f526a37