[OVN] OVN LoadBalancer VIP shouldn't have addresses set

[Maciej Jozefczyk]

While using OVN Load Balancer Octavia creates a VIP port, named ovn_const.LB_VIP_PORT_PREFIX-port_id.

Unfortunately commit [1] introduced regression. When environment has virtual port type available it fails to clear addresses field for OVN Octavia VIP port.
It should not clean it while the port is Octavia Amphore'a VIP, that internally uses keepalived to manage VIP.

[1] https://github.com/openstack/networking-ovn/commit/5e72ea104cba1c30d2de36dbbab6e3d23a075929

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/708360
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=9bd97242b65b56ee89c422b56af05a330ad3c521
Submitter: Zuul
Branch: master

commit 9bd97242b65b56ee89c422b56af05a330ad3c521
Author: Maciej Józefczyk <email address hidden>
Date: Tue Feb 18 11:37:33 2020 +0000

    Clear lsp.addresses always if port is OVN LB VIP port.

    The check _is_virtual_port_supported() prevented us from
    clearing the addresses field while port was OVN LB VIP port.
    The virtual port should be set only when port is Octavia Amphorae
    VIP port.

    Change-Id: Id6dd29650951855d13498a7206f6d1dde7db7864
    Closes-Bug: 1863893