CentOS 7.3 ships a new version of mariadb-libs which
conflicts with the version in RDO.
For p-o-i scenarios jobs this has been fixed in
https://review.openstack.org/#/c/403164/ but rspec
jobs which use openstack_integration::repos but not
run_tests.sh are still failing.
This should be reverted once a new non-conflicting package
is released by RDO.
Change-Id: Ib43ac25f96994c9373fd1e848f229ec713dd54b7
