Adding a pod causes all rack controllers to try to add it

[Andres Rodriguez]

I deployed a machine as a KVM pod with MAAS, and while tailing the logs, I noticed that all rack controllers are notified to add the pod.

This is an issue provided that MAAS should only be picking one to add the pod, and not asks all racks to do it.

node03 - where the pod was successfully added.
2019-02-05T18:47:43.187162+00:00 node03 maas.drivers.pod.virsh: [info] qemu+ssh://virsh@10.90.90.169/system?command=/usr/lib/maas/maas-virsh-ssh

node02 - another rack trying to add the pod.
2019-02-05T19:01:29.669907+00:00 node02 maas.drivers.pod.virsh: [info] qemu+ssh://virsh@10.90.90.169/system?command=/usr/lib/maas/maas-virsh-ssh
2019-02-05T19:01:31.009717+00:00 node02 maas.drivers.pod.virsh: [error] Failed to create Pod storage pool: error: Failed to define pool maas#012error: operation failed: pool 'maas' already exists with uuid fafd881e-089d-4c14-81cc-6949a4a0ad24

node01 - another rack trying to add the pod.
2019-02-05T19:01:29.668536+00:00 maas00 maas.drivers.pod.virsh: [info] qemu+ssh://virsh@10.90.90.169/system?command=/usr/lib/maas/maas-virsh-ssh
2019-02-05T19:01:29+00:00 node02 maas.drivers.pod.virsh: [info] qemu+ssh://virsh@10.90.90.169/system?command=/usr/lib/maas/maas-virsh-ssh
2019-02-05T19:01:31+00:00 node02 maas.drivers.pod.virsh: [error] Failed to create Pod storage pool: error: Failed to define pool maas#012error: operation failed: pool 'maas' already exists with uuid fafd8
81e-089d-4c14-81cc-6949a4a0ad24
2019-02-05T19:01:31.014179+00:00 maas00 maas.drivers.pod.virsh: [error] Failed to create Pod storage pool: error: Failed to define pool maas#012error: operation failed: pool 'maas' already exists with uui
d fafd881e-089d-4c14-81cc-6949a4a0ad24