fix: Fix scheduling jvb health checks.

[bgrozev]

Scheduling at a fixed rate leads to IO threads building up when a bridge
becomes unresponsibe and the duration of health checks becomes longer
than the health check interval.

[JonathanLennox]

I think your solution is the same as ScheduledExecutorService.scheduleWithFixedDelay, isn't it?

[bgrozev]

I actually used scheduleWithFixedDelay initially but it didn't go well :)

It Submits a periodic action that becomes enabled first after the given initial delay, and subsequently with the given delay

[bgrozev]

Wow, I see what you mean 🤦