fixed ThorImageField allowed_types defined multiple times
fixed ThorImageField allowed_types defined multiple times

amPerl/django-upthor,thorgate/django-upthor,Jyrno42/django-upthor,amPerl/django-upthor,thorgate/django-upthor,Jyrno42/django-upthor,Jyrno42/django-upthor,thorgate/django-upthor,amPerl/django-upthor