Fixed an error introduced in previous version.
Fixed an error introduced in previous version.

ss-dev/django-generic-ratings,papercapp/django-generic-ratings,ss-dev/django-generic-ratings,francofuji/django-generic-rating,ss-dev/django-generic-ratings,francofuji/django-generic-rating,papercapp/django-generic-ratings,francofuji/django-generic-rating,papercapp/django-generic-ratings