Protect against case where user is null.
Protect against case where user is null.

User field is nullable but some functions don't check for None before trying to access fields
legrostdg/django-knowledge,RDXT/django-knowledge,CantemoInternal/django-knowledge,7wonders/django-knowledge,zapier/django-knowledge,zapier/django-knowledge,inovasolutions/django-knowledge,zapier/django-knowledge,CantemoInternal/django-knowledge,legrostdg/django-knowledge,7wonders/django-knowledge,inovasolutions/django-knowledge,CantemoInternal/django-knowledge,RDXT/django-knowledge,legrostdg/django-knowledge,7wonders/django-knowledge,inovasolutions/django-knowledge,RDXT/django-knowledge