ensure we only compare what we need to
ensure we only compare what we need to

When comparing fingerprints, the last section is host specific - but
it's irrelevant. So we chop that bit off, and ensure that the actual
algorithm and public key still match.

dearing/chef-provisioning-fog,chef/chef-provisioning-fog,bdangit/chef-provisioning-fog,kri5/chef-provisioning-fog,chef/chef-provisioning-fog,causton81/chef-provisioning-fog,visfleet/chef-provisioning-fog,brumschlag/chef-provisioning-fog,SIGUSR2/chef-provisioning-fog,vulk/chef-metal-fog