heat: use oslo_messaging_rpc_port for nova rpc healthchecks
heat: use oslo_messaging_rpc_port for nova rpc healthchecks

See I1849926b1d6256de5f4d677de5a9b34d78aad5d0 - this patch does the same
thing but for Heat Engine service.

Change-Id: I1f49c20ce13848564181363886d5f716abb63491
Closes-Bug: #1825339

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates