api-ref: requested security groups are not applied to pre-existing ports
api-ref: requested security groups are not applied to pre-existing ports

When creating a server, you can request security groups and
pre-existing ports, but the security groups are only applied to
any new ports that nova creates, not the pre-existing ones that
the user passes in. This change makes a note of that in the API
reference.

Change-Id: I0ea6891f10f021b0ed752200417e87d7e9bfda31
Related-Bug: #1707319

jianghuaw/nova,phenoxim/nova,klmitch/nova,gooddata/openstack-nova,rahulunair/nova,klmitch/nova,vmturbo/nova,gooddata/openstack-nova,klmitch/nova,phenoxim/nova,vmturbo/nova,rahulunair/nova,jianghuaw/nova,rahulunair/nova,jianghuaw/nova,mahak/nova,mikalstill/nova,mahak/nova,openstack/nova,openstack/nova,mahak/nova,gooddata/openstack-nova,klmitch/nova,vmturbo/nova,mikalstill/nova,mikalstill/nova,openstack/nova,vmturbo/nova,gooddata/openstack-nova,jianghuaw/nova