Comment 3 for bug 1799903

Reverted https://review.openstack.org/#/c/613259/ and added the patch as a dependency in https://review.openstack.org/#/c/611329/ . This will let us confirm that the removal of {{role}}HostPrepTasks is the cause of the error, as in queens we can still deploy via Heat without using config-download (as it's the case when deploying with Ceph services enabled , as stated in https://github.com/openstack/tripleo-quickstart/commit/a0aad6e280af998b7283b465c3d83f518971d16c )