AttributeError: 'Settings' object has no attribute 'FREERADIUS_RADCHECK_SECRET_MIN_LENGTH'

[heitormsouza]

Following the installation procedure, encountered the following error:
File "/root/django-freeradius-manager/freerad_manager/django_freeradius/forms.py", line 23, in RadiusCheckAdminForm
min_length=settings.FREERADIUS_RADCHECK_SECRET_MIN_LENGTH,
File "/root/django-freeradius-manager/env/lib/python3.8/site-packages/django/conf/init.py", line 83, in getattr
val = getattr(self._wrapped, name)
AttributeError: 'Settings' object has no attribute 'FREERADIUS_RADCHECK_SECRET_MIN_LENGTH'

Environment: ubuntu server 20.04

Thanks

[peppelinux]

Please add FREERADIUS_RADCHECK_SECRET_MIN_LENGTH to your project settings

If possible and of you can, please open a PR to add this hint in the readme/doc