fix<tickets>: Force HELPDESK_PUBLIC_TICKET_QUEUE for anon tickets
fix<tickets>: Force HELPDESK_PUBLIC_TICKET_QUEUE for anon tickets

Before: we set initial value for the widget and had it hidden. So user could still change the queue with some HTML knowledge.

Now: we drop the field at all and assign queue directly, utterly ignoring the POST request content for "queue" field.

gwasser/django-helpdesk,django-helpdesk/django-helpdesk,django-helpdesk/django-helpdesk,gwasser/django-helpdesk,rossp/django-helpdesk,django-helpdesk/django-helpdesk,rossp/django-helpdesk,django-helpdesk/django-helpdesk,rossp/django-helpdesk,rossp/django-helpdesk,gwasser/django-helpdesk,gwasser/django-helpdesk