Comment 1 for bug 1506925

Reviewed: https://review.openstack.org/216441
Committed: https://git.openstack.org/cgit/openstack/django_openstack_auth/commit/?id=885cdd96c630fa225a2e7417f541ddfeb335bd89
Submitter: Jenkins
Branch: master

commit 885cdd96c630fa225a2e7417f541ddfeb335bd89
Author: Kirill Zaitsev <email address hidden>
Date: Tue Aug 25 01:02:28 2015 +0300

    Use set comprehension instead of converting lists to sets

    This patch takes advantage of python set comprehensions
    syntax instead of constructing a list and converting
    it to set later.
    Also takes advantage of .isdisjoint function,
    that returns True if two sets have a null intersection.
    Should slightly improve performance and readability.

    Closes-Bug: #1506925
    Change-Id: Ia3d8b47efcf1b2280d7570e782fd196ce716ac8a