exclude '\r' from subject_part
exclude '\r' from subject_part

This is to prevent BadHeaderError("Header values can't contain newlines..
temnoregg/django-helpdesk,iedparis8/django-helpdesk,mrkiwi-nz/django-helpdesk,gwasser/django-helpdesk,django-helpdesk/django-helpdesk,fjcapdevila/django-helpdesk,rossp/django-helpdesk,iedparis8/django-helpdesk,chriscauley/django-helpdesk,iedparis8/django-helpdesk,iedparis8/django-helpdesk,rossp/django-helpdesk,temnoregg/django-helpdesk,fjcapdevila/django-helpdesk,harrisonfeng/django-helpdesk,gwasser/django-helpdesk,django-helpdesk/django-helpdesk,harrisonfeng/django-helpdesk,harrisonfeng/django-helpdesk,django-helpdesk/django-helpdesk,mrkiwi-nz/django-helpdesk,gwasser/django-helpdesk,harrisonfeng/django-helpdesk,chriscauley/django-helpdesk,rossp/django-helpdesk,chriscauley/django-helpdesk,gwasser/django-helpdesk,temnoregg/django-helpdesk,django-helpdesk/django-helpdesk,chriscauley/django-helpdesk,fjcapdevila/django-helpdesk,rossp/django-helpdesk,mrkiwi-nz/django-helpdesk,temnoregg/django-helpdesk,fjcapdevila/django-helpdesk,mrkiwi-nz/django-helpdesk