address pairs in update request always trigger agent notification

[Salvatore Orlando]

currently some plugins always notify the agent of a port_update even if the allowed address pairs attribute is specified: https://github.com/openstack/neutron/blob/master/neutron/plugins/ml2/plugin.py#L600

However, if there's no change in allowed address pairs there is no need for triggering a notification

Affected plugins:
ml2
openvswitch
nec

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/58566

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/58566
Committed: http://github.com/openstack/neutron/commit/eb23b345876796f4002cab3632bad1c840289d04
Submitter: Jenkins
Branch: master

commit eb23b345876796f4002cab3632bad1c840289d04
Author: Salvatore Orlando <email address hidden>
Date: Tue Nov 26 08:18:17 2013 -0800

    Rebind allowed address pairs only if they changed

    This patch ensures allowed address pairs bindings are refreshed
    only when they actually change.
    This will also avoid sending a notification to the agent if no
    change actually occured.

    Closes-Bug: #1255145
    Partial blueprint neutron-tempest-parallel

    Change-Id: Iac2502586a0d215a29194590c16c2e1a064f943b