Update graylog2ctl

Fixes the error "/usr/bin/nohup: redirecting stderr to stdout", for me on a fresh install of Ubuntu 14.04.1. References for this fix can be found at either http://www.tldp.org/LDP/abs/html/io-redirection.html or http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-3.html