Comment 2 for bug 1696215

Reviewed: https://review.openstack.org/471861
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=e9cd1bc89e5610de84b116d6c3687d4f796f527c
Submitter: Jenkins
Branch: master

commit e9cd1bc89e5610de84b116d6c3687d4f796f527c
Author: Patrick East <email address hidden>
Date: Tue Jun 6 13:51:01 2017 -0700

    Allow Pure drivers to handle detach with no host

    Apparently force-detach is ok with no connector
    object passed in. This changes the driver to assume
    that no connector means just detach the volume from
    anything its attached to.

    I updated the base driver to document this quirk
    too.

    This should only ever happen with force detach and
    "old" style connections, which means multi-attach
    shouldn't be in the picture so this is kind of
    safe... probably..

    Change-Id: Ia0710d66bdbc85afffdb6e4f22f3ce6ca642ec75
    Closes-Bug: #1696215