Update port profile only if defined
Update port profile only if defined

Change[1] added port profile configuration option.
We need to update port only if needed.

[1] https://review.openstack.org/#/c/499575

Change-Id: Ifada5a357d9a09ade7737c5fa8af1422b9353924

masayukig/tempest,masayukig/tempest,cisco-openstack/tempest,openstack/tempest,cisco-openstack/tempest,openstack/tempest