Handle failure to get endpoint from device registry better

[laurigates]

At the moment this is what happens if endpoint starts when the device registry is down:

[2023-10-25 08:07:23,138] INFO in __init__: Initializing sentry: *************
[2023-10-25 08:07:23,765] ERROR in app: Failed to get endpoints from device registry http://mittaridatapumppu-deviceregistry:8080/api/v1/hosts/localhost/
[2023-10-25 08:07:23,768] INFO in aiokafka: Getting KafkaProducer: kafka-kafka-bootstrap:9093
[2023-10-25 08:07:23,830] INFO in app: Ready to go, listening to endpoints:

And it doesn't check for it again so it stays in this state.