When using the PKI token provider, it is necessary to
ensure that a secure hashing algorithm is used. The
charms never configure a PKI provider but the checklist
action is still a valid runtime check.

Change-Id: If0869124e4fcf7af68f636b9e4d3027c83407a4f
Closes-Bug: 1820813
Func-Test-PR: https://github.com/openstack-charmers/zaza/pull/200