Updated openstack/openstack
Project: openstack/nova  cc2129a72ad45a733d75bbf8f0a9b94f2882fd82

Clearer default implmentation for dhcp_options...

'pass' is less clear than 'return None' for the base implementation.

Change-Id: Iff53d5eb7e88e18849696d858b3d910b6ea71e63