scenario003: disable mistral
scenario003: disable mistral

https://bugs.launchpad.net/mistral/+bug/1663368

Change-Id: Ifb86cdf221d114aefa8f1c28cbddd5d245c6b386
Related-Bug: #1663368

openstack/puppet-openstack-integration,openstack/puppet-openstack-integration,openstack/puppet-openstack-integration