update config-external.sh in galera,keystone,rabbitmq,swift

[XiaBing Yao]

The config-external.sh content in rabbitmq and glance is
the different style,like follow:

kolla/docker_templates/rabbitmq/config-external.sh:
# Cluster configuration # Cluster configuration
if [[ -f /opt/kolla/rabbitmq/rabbitmq.config ]]; then
     cp -af /opt/kolla/rabbitmq/rabbitmq.config /etc/rabbitmq/rabbitmq.config
     chown rabbitmq: /etc/rabbitmq/rabbitmq.config
     chmod 0600 /etc/rabbitmq/rabbitmq.config

if [[ -f /opt/kolla/rabbitmq/rabbitmq-env.conf ]]; then
     cp -af /opt/kolla/rabbitmq/rabbitmq-env.conf /etc/rabbitmq/rabbitmq-env.conf
     chown rabbitmq: /etc/rabbitmq/rabbitmq-env.conf
     chmod 0600 /etc/rabbitmq/rabbitmq-env.conf
fi

kolla/docker_templates/glance/glance-api/config-external.sh:
#!/bin/bash
SOURCE="/opt/kolla/glance-api/glance-api.conf"
TARGET="/etc/glance/glance-api.conf"
OWNER="glance"

if [[ -f "$SOURCE" ]]; then
    cp $SOURCE $TARGET
    chown ${OWNER}: $TARGET
    chmod 0644 $TARGET
fi

I think it's better to use variables SOURCE and TARGET in
config-external.sh to keep consistant with glance, so it
will easy to modify it in future, and galera,keystone,swift
have the same issue.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/213787
Committed: https://git.openstack.org/cgit/stackforge/kolla/commit/?id=b11321cedcfca8c394eefffae9589eba9b470fa2
Submitter: Jenkins
Branch: master

commit b11321cedcfca8c394eefffae9589eba9b470fa2
Author: xiabing.yao <[e-mail]>
Date: Thu Aug 6 17:32:56 2015 +0800

    update config-external.sh in galera,keystone,rabbitmq,swift

    Use variables like SOURCE,TARGET in config-external.sh, so
    it will easy to modify in future.

    Closes-Bug: #1485710

    Change-Id: I3880a2cbca8a80d36e84a797fcfb943e43b88bd5