schedued threads running evening kamon is disabled

```
"io.kamon" % "sbt-kanela-runner-play-3.0" % "2.1.0"
"io.kamon" %% "kamon-play" % "2.7.7" 

```
kamon-agent-cache-pool-cleaner and 
kamon-agent-periodic-resubmitter-scheduler still running even  

`kamon.enabled = false`