Comment 5 for bug 1621109

Reviewed: https://review.openstack.org/366750
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=b66d4d997cf371d4d451aa9e57d351f4e045fc8d
Submitter: Jenkins
Branch: master

commit b66d4d997cf371d4d451aa9e57d351f4e045fc8d
Author: Kaitlin Farr <email address hidden>
Date: Wed Sep 7 13:21:33 2016 -0400

    Modifies override logic for key_manager

    Makes the logic for overriding config options for the key_manager
    more robust.

    Before this patch, the override logic seemed to be called before the global
    CONF object has been populated with values from the configuration file.
    ConfKeyManager, the default for if no value had been specified, would be
    used to override the value for api_class. Then when CONF was populated
    with the actual values, the ConfKeyManager override value would still be
    set.

    This patch makes the logic a little bit more robust so that the value
    is only overriden if explicitly passed into the function, not at the
    global scope outside of the function.

    SecurityImpact

    Closes-Bug: 1621109
    Change-Id: Id5f83f69fd3a877459fab924c005047e55f98c7b