alembic autogenerate detects table deletion of service plugins

[Akihiro Motoki]

When I run neutron-db-manage revision --autogenerate, it detects lbaas table deletion
even when loadbalancer service plugins are declared in neutron.conf.

The reason is table definitions of service plugins are not loaded when "revision --autogenerate" is run.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44276

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44276
Committed: http://github.com/openstack/neutron/commit/55bfb412f1732e97da76f1b34e581d2429df38e6
Submitter: Jenkins
Branch: master

commit 55bfb412f1732e97da76f1b34e581d2429df38e6
Author: Akihiro MOTOKI <email address hidden>
Date: Thu Aug 29 21:08:06 2013 +0900

    Load tables of service plugins when migration auto generation

    When we run "neutron-db-manage revision --autogenerate", it detects
    table deletion of service plugins even when they are configured.
    We need to load tables of service plugins to teach alembic such
    tables exist.

    Change-Id: I9186d36496069c8253683bd200326b80a6565fa6
    Closes-Bug: #1218338