Disable connecting to plug.dj.

Plug.dj [changed their
API](http://blog.plug.dj/2013/07/attention-all-extension-developers/)
without detailing what changes were made, so until we get the
opportunity to fix this in chrisinajar/plugapi I'm disabling the bot's
attempts to connect to the site in favor of allowing the stats tracking
site to remain available (mainly so we can use [the collected data for
Coding Soundtrack](http://codingsoundtrack.org) in the development of
soundtrack.io!).
Merge branch 'master' of github.com:martindale/snarl