Comment 4 for bug 1573207

Reviewed: https://review.openstack.org/309651
Committed: https://git.openstack.org/cgit/openstack/networking-arista/commit/?id=a55152054688310e9dc57156aa3a41ce21003930
Submitter: Jenkins
Branch: stable/kilo

commit a55152054688310e9dc57156aa3a41ce21003930
Author: Sukhdev Kapur <email address hidden>
Date: Fri Apr 22 22:19:20 2016 -0700

    Do not delete a network with ports attached to it

    If a network has ports attached to it, do not delete the network
    instead raise an exception so that user knows about this
    condition.

    Additionally, during initialization, when networks are deleted,
    remove all the ports associated with the network.

    This manual cherry picking becuase of split of repos in stable/kilo

    Closes-bug: #1573207
    cherry picked from Change-Id: Idb72305ac37dfe0c865fe09fbc5ab784d807906d

    Change-Id: I5c570fc6ad1cb0eb885a105213b253a222cd68a2