Since transient_queues_ttl is also managed by oslo::messaging::rabbit,
there's no way to use ironic_config to set it, so this patch is mandatory
for one to set rabbit_transient_queues_ttl in ironic.conf.
Same applies to ironic_inspector_config.
Change-Id: I95625460e2b79cd071819edc6b397cae907c9bf4