Remove LetsEncrypt certbot cronjob.
Remove LetsEncrypt certbot cronjob.

This list of Ansible tasks was originally created for Debian 8 (Jessie)
servers, which did not include certbot as a package. Since we now
install certbot through Debian, including a separate cron job is
superfluous and wasteful.

pydata/conf_site,pydata/conf_site,pydata/conf_site