Comment 6 for bug 1566678

Reviewed: https://review.openstack.org/308142
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=6b33c51a32e075c57630160b5b0544ad29f1a3bb
Submitter: Jenkins
Branch: stable/liberty

commit 6b33c51a32e075c57630160b5b0544ad29f1a3bb
Author: Kevin Benton <email address hidden>
Date: Mon Feb 1 01:17:22 2016 -0800

    Only prevent l3 port deletion if router exists

    This patch modifies the prevent_l3_port_deletion method to
    actually look up the router_id in the device_owner field to
    confirm that the router exists before claiming the port is
    in use. This will allow users to delete ports that may have
    been orphaned due to race conditions in the cleanup of router
    interfaces.

    Conflicts:
     neutron/tests/unit/db/test_l3_db.py

    Closes-Bug: #1566678
    Partial-Bug: #1540271
    Change-Id: Ieffe632f3f3098baf202d3795ab5182982e234bd
    (cherry picked from commit 3b41808b8624f5442d65ba638d1a2c1bdc22be00)