With all https://tickets.chaos.jetzt/shortcode links will redirect to
the appropriate ticket-shop without a need for us to place manual
redirect links.
With https://github.com/chaos-jetzt/website_pelican/pull/33, a lot of
orphans are to be expected which will take up space on our servers. This
introduces a timer which runs once a week and will delete any
website generations older than 28 days.
The actual 404 will be generated from pelican. log_not_found was set for
privacy reasons (since we don't have a favicon, every request still gets
logged with it's full IP due to the 404)
