[CI] SimpleNetty4TransportTests.testTimeoutPerConnection failure

[romseygeek]

https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+5.6+multijob-windows-compatibility/975/console

Seems flaky, and I can't reproduce it.

[elasticmachine]

Pinging @elastic/es-core-infra

[DaveCTurner]

Closing this. The build logs are long gone and this hasn't recurred, so there's not much action we can take here.