Update liaison for networking-sfc project
Update liaison for networking-sfc project

During Shanghai PTG Akihiro talked with Dharmendra, who is the Tacker
PTL that Dharmendra can be maintainer of networking-sfc project for now
as Tacker is using this project.
So lets say that officially in our documentation now.

Change-Id: Iea9fbf997130e95252fcd1063fd7a28ad84dd369

mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron,mahak/neutron,openstack/neutron