Use barbican.conf instead of barbican-api.conf
Use barbican.conf instead of barbican-api.conf

Since barbican-api.conf was deprecated in favor of barbican.conf
this change needs to also be reflected in the code that actually loads
the configuration in the server. This change properly reflects that.

Change-Id: I243fe7d98fda9bd4ceeb8850c7747f9bd8250b00

openstack/barbican,openstack/barbican