Disable queue mirroring for RPC queues in RabbitMQ

As a member of the Oslo team looking to optimize Oslo performance without sacrificing high availability for the highest priority messages, I would like to remove HA queue mirroring on all queues except Ceilometer notification and Audit queues so that I can test the performance at the new configuration and determine the performance difference against all queues being HA mirrored.

First we need to remove HA queues mirroring for RPC queues, leave it on only for Ceilometer notification and Audit queues.
Then we will test such approach on scale using worst scenario for RabbitMQ we have at the moment. We will measure RabbitMQ's cpu and memory usage and, if we see significant reduction, we can accept the change.