Updates job failing on rabbit long name error

[Ben Nemec]

The updates job appears to have been broken by https://review.openstack.org/#/c/403547 All of the jobs are failing to start rabbit with the following error:

Can't set long node name!\nPlease check your configuration\n

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/406183

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/406183
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=0f1022e8ee2c9e7bbe40ba905c15a40a27708df6
Submitter: Jenkins
Branch: master

commit 0f1022e8ee2c9e7bbe40ba905c15a40a27708df6
Author: Ben Nemec <email address hidden>
Date: Fri Dec 2 15:45:21 2016 +0000

    Revert "Use FQDN for rabbitmq's nodename env variable"

    This seems to have broken the updates job, causing it to fail
    with following error:

    Can't set long node name!\nPlease check your configuration\n

    Related-Bug: 1646873

    This reverts commit 3e9fcfd09320ace07bc1bd4cb57feb98cd057332.

    Change-Id: I72ba891cd9cd8c4f1bc204144f46aaabbdfd3647

[Ben Nemec (bnemec)]

I'm actually going to mark this fix released since we reverted the patch that broke it. There isn't really a separate fix needed here, we just need to make sure we don't merge another version of the change that doesn't work with ipv6.