www/py-django-sekizai: Update to 1.1.0

• Keep it assigned to Django 1.11 for a short while because it will be switched to Django 2.2 once www/py-django-cms gets updated.

• Remove the DOCS option and relevant variables because the documentation specific files are no longer supplied with the sdist tarball.

Changelog:

https://github.com/divio/django-sekizai/blob/1.1.0/CHANGELOG.rst

PR: 245361
Approved by: maintainer timeout (14 days)