When the worker is started with `-restart-exit-code 47` or has
`restart_exit_code=47` in `flamenco-worker.yaml`, it's marked as
'restartable'. This will enable two worker actions 'Restart
(immediately)' and 'Restart (after task is finished)' in the Manager web
interface. When a worker is asked to restart, it will exit with exit
code `47`. Of course any positive exit code can be used here.
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