Comment 5 for bug 1822100

Reviewed: https://review.openstack.org/650238
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=234fcd61aa0ed195639769c746acc0e6d318b154
Submitter: Zuul
Branch: stable/stein

commit 234fcd61aa0ed195639769c746acc0e6d318b154
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Tue Apr 2 16:57:17 2019 +0100

    Allow provider net attr in update if no change

    If provider net attributes are in update request body,
    do an additional check to see if the values are actually
    different. Only raise exception if values are different.

    This backport partially picks change:
    I2595335d6fbc51562b070f14eaeaadf49cf7c418. Specifically
    the refactoring replacing the neutron.extensions.providernet
    _raise_if_updates_provider_attributes method with the
    neutron.plugins.ml2.plugin _update_provider_network_attributes
    method.

    Conflicts:
            neutron/extensions/providernet.py
     neutron/plugins/ml2/plugin.py
     neutron/tests/unit/plugins/ml2/test_plugin.py

    Closes-Bug: #1822100
    Co-Authored-By: Rodolfo Alonso Hernandez <email address hidden>

    Change-Id: I4ac11299375d1d3a7d2013f1fdc1742920d884a9
    (cherry picked from commit 20743350b9b40fd7a2cff074bb2c877ea36c5914)