api: Fix client.AddNeighbor() API does not properly configure AFI/SAFI bug
api: Fix client.AddNeighbor() API does not properly configure AFI/SAFI bug

When we use gRPC API to add neighbor. Even if we specify,
config.Neighbor.AfiSafis parameter, it is ignored in
NewPeerFromConfigStruct(). Adding to that even if we fix the issue,
NewNeighborFromAPIStruct() count Families twice. So resulting neighbor
has duplicated Families configuration. This patch fixed both problems.

a16/gobgp,a16/gobgp,osrg/gobgp,a16/gobgp,tamihiro/gobgp,a16/gobgp,osrg/gobgp,Dipsingh/gobgp,fujita/gobgp,ishidawataru/gobgp,ishidawataru/gobgp,Dipsingh/gobgp,fujita/gobgp,a16/gobgp,j-kato/gobgp,tamihiro/gobgp,ishidawataru/gobgp,osrg/gobgp,tamihiro/gobgp,fujita/gobgp,j-kato/gobgp,fujita/gobgp,tamihiro/gobgp,osrg/gobgp,Dipsingh/gobgp,a16/gobgp,j-kato/gobgp,a16/gobgp