Remove call to nb_api.initialize in bgp service
Remove call to nb_api.initialize in bgp service

nb_api.initialize is already called in get_instance, which is already
called by the BGP service. This call is redundant.

The bug is related for two reasons:
1. This is how this duplication was found
2. It removed references to remote_db_port and remote_db_ip

Change-Id: I3afc40a12073630f1f0a7ce54b5bb794ba2db06a
Related-Bug: #1627229

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow