Fix comment about default implementations
Fix comment about default implementations

Fix coment about default implementations.
The Python implementations are the default
implementations.

Change-Id: I76a77d017602a33dfe4221d683ff4557c24eecca

stackforge/monasca-api,openstack/monasca-api,openstack/monasca-api,sapcc/monasca-api,stackforge/monasca-api,stackforge/monasca-api,sapcc/monasca-api,openstack/monasca-api,sapcc/monasca-api,stackforge/monasca-api