We can start multiple mysql masters if mysql.nodes is undefined

[Julia Kreger]

When an overcloud stack is booted with a CONTROLSCALE being greater than 1 and no mysql cluster configuration exists in the heat template (mysql.nodes), then the resulting MySQL configuration that is placed on disk is one of a master node. This should be aborted instead of silently allowed to continue onward during the os-refresh-config process.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/104414

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/104414
Committed: https://git.openstack.org/cgit/openstack/tripleo-image-elements/commit/?id=a08a0d87c9748b9f6f7d90ce95d981b526a3e677
Submitter: Jenkins
Branch: master

commit a08a0d87c9748b9f6f7d90ce95d981b526a3e677
Author: Julia Kreger <email address hidden>
Date: Wed Jul 2 22:00:38 2014 -0400

    Prevent multiple MySQL masters

    When CONTROLSCALE is set to >1 and no mysql.nodes are configured, the
    previous behavior resulted in MySQL being configured as a master node
    on all control nodes.

    This change detects that condition and returns an error to
    os-refresh-config if encountered.

    Change-Id: I7837a8496a316775b6f0a399e6c237a25a9a24d4
    Closes-Bug: 1336915