Comment 4 for bug 1439959

Reviewed: https://review.openstack.org/176124
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=d61ba3ba5222dd6338528cbb4232df6ed959f540
Submitter: Jenkins
Branch: stable/kilo

commit d61ba3ba5222dd6338528cbb4232df6ed959f540
Author: Kanagaraj Manickam <email address hidden>
Date: Mon Apr 6 10:52:57 2015 +0530

    Cleans nullable=True in db model column declaration

    By default sqlalchemy considers the Column's nullable=True and
    this patch cleans those column declaration which is having
    default value for the nullable field as it is not required
    explicitly

    Change-Id: I22b0d62238298fa49da09c53019408bc2049b893
    Closes-bug: #1439959
    (cherry picked from commit 1dbb1ed98f98a8b474f4d54df6554e4e1d93a296)