fixing infinte errors when munin node dies

* `gets` might return nil when the socket is closed
  see http://www.ruby-forum.com/topic/2523071
* raising an EOFError when this happens to prevent
  infinite loop sending bazillion of syslog errors...
changed tabbing to match previous line
Merge pull request #1 from gingerlime/master

fix: if munin drops socket, then errors are syslogged in an infinite loop