Do not fail deploy for empty ceph ansible fetch directory
Do not fail deploy for empty ceph ansible fetch directory

The RestoreTempDirFromSwift action returned an error if
the Swift container is empty which can stop a deployment.
However there are legitimate reasons the Swift container
could be empty for which the deployment should not be
stopped.

Change-Id: Ic2d9f31caaacbf1c83c4c716cd5e282c6a1953f0
Closes-Bug: #1803609

openstack/tripleo-common,openstack/tripleo-common