www/py-django-registration: Update to 3.1
- Switch the port to Django 2.2 (current LTS release) because Django 1.11 is End-of-Life since April.
- Sort variables a bit according to the PHB and clean up CONFLICTS_INSTALL entry as textproc/pootle is no longer present in the Ports tree.
- Remove Python 2.7 support of www/py-django-registration-defaults to avoid breakage of "bulk -a".
Changelog:
https://github.com/ubernostrum/django-registration/blob/3.1/docs/upgrade.rst
PR: 245902
Approved by: Kevin Golding <ports@caomhin.org> (maintainer)