[SAC] Letsencrypt enabled for europe.foss4g.org

[Sandro Santilli]

I've enabled HTTPS for europe.foss4g.org using letsencrypt
certificate: https://europe.foss4g.org

The sysadmin at osgeo mail was used to register with the service,
so that's were notices of expiration will be sent.

Renewal is performed montly (1st of every month, at 1:30am)
via cron (sudo crontab -e).

Letsencrypt SSL certificates are under /etc/letsencrypt,
which was put under GIT revision control (to more easily
spot what changed).

On the apache side, I added a letsencrypt-options-ssl.conf
file to /etc/apache/sites-available to be included from
site configurations willing to do SSL with letsencrypt.

Let's see how things go for a few months and then we
can switch other services (planet?).

--strk; 

  ()   Free GIS & Flash consultant/developer
  /\   https://strk.kbt.io/services.html