Repo-copy www/py-django-auth-ldap and assign it to Django 2.1 to enable LDAP authentication with net-mgmt/netbox that has been switched to Django 2.1 recently.
Also limit the port to Python 3.5+ as Django 2.1 requires it as minimum dependency and to save some overhead in the building infrastructure.
Requested by: Thomas Kurschel (via private email)
Approved by: (one of the mentors)