Comment 0 for bug 1713592

Incase of Single-interface topology when 3 node HA both being contrail, Openstack
JSON should take "blank value for control/data interface and also for external VIP values"

currently, JSON forcing to have control/data interface specific and external VIP values otherwise provisioing aborted with exceptions as below,

"2017-08-28 14:45:45,350-ERROR-server_mgr_main.py:4748-log_trace(): *****TRACEBACK-START*****"
"2017-08-28 14:45:45,351-ERROR-server_mgr_main.py:4752-log_trace(): Traceback (most recent call last):
"
"2017-08-28 14:45:45,352-ERROR-server_mgr_main.py:4752-log_trace(): File "/opt/contrail/server_manager/server_mgr_main.py", line 6655, in provision_server
    self.prepare_provision(ret_data)
"
"2017-08-28 14:45:45,353-ERROR-server_mgr_main.py:4752-log_trace(): File "/opt/contrail/server_manager/server_mgr_main.py", line 6478, in prepare_provision
    self._smgr_validations.validate_vips(cluster_id, self._serverDb)
"
"2017-08-28 14:45:45,354-ERROR-server_mgr_main.py:4752-log_trace(): File "/opt/contrail/server_manager/server_mgr_validations.py", line 334, in validate_vips
    raise e
"
"2017-08-28 14:45:45,355-ERROR-server_mgr_main.py:4752-log_trace(): Exception: Both internal and external vips have to be configured
"
"2017-08-28 14:45:45,356-ERROR-server_mgr_main.py:4753-log_trace(): *****TRACEBACK-END******"