Debian upgrade complete

Hisoka was upgraded to Debian 9 (stretch) today. Apart from some touchy configuration (looking at you dovecot and mariadb) it went pretty well. The server was also rebooted to use the latest available Linux kernel, thus resetting our uptime after nearly 500 uneventful days.

As usual, if you notice some of your stuff is broken after this update, please holler at me and I’ll fix it as soon as I can!