Fixed #7527 -- Removed an unused value from __all__ in...

Fixed #7527 -- Removed an unused value from __all__ in django.core.servers.basehttp. It had languished there erroneously since the original checkin in Django changeset [174]. Thanks, trevor

git-svn-id: http://code.djangoproject.com/svn/django/trunk@7746 bcc190cf-cafb-0310-a4f2-bffc1f526a37