Healthcheck: StartInterval

[xarem]

Currently, the health check runs every 30s. Even if our container boot only takes some seconds, this means, the reverse proxy sends the first traffic after 30 seconds after starting the container if the container is healthy at this time.

With Docker Engine 25.0, a new "StartInterval" configuration was introduced to mark the container as started / healthy more quicky:

moby/moby#40894

We should add this to our healthcheck.