Almost the same as upstream rumqttd, except disabling profiling, disabling TLS, and configuring the logging via the commandline.
This isn't a solution I'm happy with, as it still has the Warp dependency for the console, something I do not wish to have.
It also only supports hard-coded Listen addresses and not socket-activation, another misfeature for the way we wish to use the MQTT broker.
The config file needs to match rumqttd config. See: https://github.com/bytebeamio/rumqtt/tree/master/rumqttd