This change defaults the warning-as-error to True:
https://review.openstack.org/#/c/559348/
Which is causing our documentation jobs to fail locally and in the
gate/check queues.
This commit fixes both issues that are causing failures so that
we can get the doc jobs passing again.
Change-Id: I5dd71b6c69b975f8dd922aa3cab9d027f535f422
(cherry picked from commit 64d62a54f6)