simplifying if-case branches on CustomFieldMixin
simplifying if-case branches on CustomFieldMixin

gwasser/django-helpdesk,django-helpdesk/django-helpdesk,django-helpdesk/django-helpdesk,mrkiwi-nz/django-helpdesk,rossp/django-helpdesk,rossp/django-helpdesk,gwasser/django-helpdesk,gwasser/django-helpdesk,django-helpdesk/django-helpdesk,django-helpdesk/django-helpdesk,mrkiwi-nz/django-helpdesk,mrkiwi-nz/django-helpdesk,mrkiwi-nz/django-helpdesk,gwasser/django-helpdesk,rossp/django-helpdesk,rossp/django-helpdesk