Comment 2 for bug 1769609

Reviewed: https://review.openstack.org/615206
Committed: https://git.openstack.org/cgit/openstack/neutron-tempest-plugin/commit/?id=21f5342de8b36c3c033d959b63451723e4fdbcf3
Submitter: Zuul
Branch: master

commit 21f5342de8b36c3c033d959b63451723e4fdbcf3
Author: Slawek Kaplonski <email address hidden>
Date: Fri Nov 2 16:02:09 2018 +0100

    Fix creating subnet without gateway

    If create_subnet() method is called with gateway=None explicity,
    subnet should be created without gateway_ip specified.
    To achieve that "gateway_ip=null" should be passed in json in
    request's body to neutron server.
    This was missing, so neutron-server allocated gateway_ip automatically.
    Now gateway for such network will not be set as is expected.

    Closes-Bug: #1769609

    Change-Id: Ia9f0646a3cf371f82f2aa2dc22837249531d1ff5