The logstash::indexer no longer sets up the mqtt output plugin for
logstash. So we don't need to keep the options around to enable it and
write the create the cert file. This commit removes those pieces.
Change-Id: I6ebdb5dc8fea8309609d837a758eeaf1dc5ee760
Depends-On: I6becec12604c61fe50d3e6b9c7ed9f9e9be311ae