logging: replace rsyslog with logstash-forwarder

A task to restart a service that isn't currently running results in the service being started. That's acceptable, it gets the new config read. It gracefully handles the fact that the service wasn't already running.

Without the flush, what you wind up doing is starting the service and then immediately restarting the service. While for some services this isn't a big deal, others this can be a real pain in the arse. As a operational pattern, I feel it's better to arrange things to avoid immediate restarts, regardless of the service.