Add info on upgrading to system settings model
Add info on upgrading to system settings model

yan99uic/django-DefectDojo,OWASP/django-DefectDojo,rackerlabs/django-DefectDojo,grendel513/django-DefectDojo,OWASP/django-DefectDojo,grendel513/django-DefectDojo,OWASP/django-DefectDojo,grendel513/django-DefectDojo,OWASP/django-DefectDojo,OWASP/django-DefectDojo,yan99uic/django-DefectDojo,grendel513/django-DefectDojo,yan99uic/django-DefectDojo,yan99uic/django-DefectDojo,rackerlabs/django-DefectDojo,rackerlabs/django-DefectDojo,rackerlabs/django-DefectDojo