Instead of text_data use key_data property to check for uniqueness.
Brown paper bag fix, querying for TextProperty is not smart ^_^.
Patch by: Lennard de Rijk, Sverre Rabbelier
Reviewed by: to-be-reviewed
"""
>>> from django.contrib.sites.models import Site
>>> from django.conf import settings
>>> Site(id=settings.SITE_ID, domain="example.com", name="example.com").save()
>>> # Make sure that get_current() does not return a deleted Site object.
>>> s = Site.objects.get_current()
>>> isinstance(s, Site)
True
>>> s.delete()
>>> Site.objects.get_current()
Traceback (most recent call last):
...
DoesNotExist: Site matching query does not exist.
"""