Comment 4 for bug 1747936

Reviewed: https://review.openstack.org/542964
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=dc2d15129d1a86a841e3dc1ccab250c30d34c540
Submitter: Zuul
Branch: master

commit dc2d15129d1a86a841e3dc1ccab250c30d34c540
Author: Surya Seetharaman <email address hidden>
Date: Fri Feb 9 18:54:05 2018 +0100

    Unmap compute nodes when deleting host mappings in delete cell operation

    Presently when a host_mapping is deleted during the nova-manage cell_v2
    delete_cell operation, the compute node record still remains with its
    mapped field set to 1. Due to this, if we delete a cell, and later
    create a new cell, the discover_hosts command will not work and the
    compute node will not get mapped to the new cell. This patch fixes this
    issue by setting it back to 0.

    Change-Id: Iaf13f11bcd0bb25f673fc28f252cb9391409b9b5
    Closes-Bug: #1747936