fix flake8 issues
fix flake8 issues

OWASP/django-DefectDojo,rackerlabs/django-DefectDojo,rackerlabs/django-DefectDojo,OWASP/django-DefectDojo,OWASP/django-DefectDojo,rackerlabs/django-DefectDojo,rackerlabs/django-DefectDojo,OWASP/django-DefectDojo,OWASP/django-DefectDojo