The launchd bootstrap already starts the gateway job. The subsequent
kickstart -k was killing it immediately after startup, and combined
with KeepAlive=true, this caused a port-conflict restart loop where
launchd would try to restart while the old instance was still
shutting down.
Symptoms: 'Bootstrap failed: 5: Input/output error' and repeated
'Gateway failed to start: another gateway instance is already
listening' messages in the log.