enabled emulation query should request no attributes

[Brant Knudson]

When keystone does the ldap_search for the "enabled emulation" entry, it asks for the "cn" attribute to be returned. Since keystone doesn't use the cn attribute from the result, there's no need for it to request this attribute, and it would be slightly more efficient to request no attributes instead since there's less data for the LDAP server to return.

[Brant Knudson (blk-u)]

https://review.openstack.org/#/c/187065

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/187065
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=fbc52833d668a7575e65eb5494dbc4c7a2b4b3d1
Submitter: Jenkins
Branch: master

commit fbc52833d668a7575e65eb5494dbc4c7a2b4b3d1
Author: Brant Knudson <email address hidden>
Date: Sun May 31 11:46:56 2015 -0500

    Correct enabled emulation query to request no attributes

    The enabled emulation query was requesting that the cn attribute
    be returned, but it didn't use the attribute value. This query
    should have specified that no attributes be returned since this is
    slightly more efficient as no extra data needs to be retrieved.

    Closes-Bug: 1482687
    Change-Id: I9f3cb80d02236498174e7962e3c1283386589ee2