By default erlang VM determines a number of scheduler threads equal to a
number of CPU cores it detects [0]. Running rabbitmq in container makes
Erlang VM to think it has all host CPU power, making extra scheduler
threads competing for CPU time and, depending on a difference between
a number host CPU cores and container limits, causing CPU throttling even
while idle.
This commit limits a number of schedulers to a value actually available
to container via k8s resource limits (min 1) emulating the default
behavior.
[0] https://www.rabbitmq.com/runtime.html#scheduling
Change-Id: If36f63173de4c8035daf7aac4014c027c579b58f
1a8536fd5d