Create localhost exception for POST /unauth/users API call
The purpose of this request is for Ops Manager to implement a "localhost exception" for the API call POST /unauth/users so it can only be executed under two conditions:
1. No other users exists in the setup.
1. Ops Manager runs in "invitation only" mode.
1. Ops Manager has not been configured for LDAP.
1. The API call can only originate from an IP or alias that belongs to one of the Ops Manager Application server.