server: fix bug when you add a neighbor config in grpc

Gobpg does not  set AfiSafi if NeighborConfig is configured  via gRPC, this issue causes error when Gobgp receives route from the Peer.

log of following when peer was down
```
DEBU[0009] received                                      Key=192.168.100.2 Topic=Peer data=&{Header:{Marker:[] Len:19 Type:4} Body:0xe17ff0}
WARN[0010] malformed BGP update message                  Key=192.168.100.2 Topic=Peer error=Address-family rf 65537 not avalible for session
WARN[0010] sent notification                             Data=&{Header:{Marker:[] Len:21 Type:3} Body:0xc8200117a0} Key=192.168.100.2 State=BGP_FSM_ESTABLISHED Topic=Peer
INFO[0010] Peer Down                                     Key=192.168.100.2 Reason=Peer closed the session State=BGP_FSM_ESTABLISHED Topic=Peer
DEBU[0010] state changed                                 Key=192.168.100.2 Topic=Peer new=BGP_FSM_IDLE old=BGP_FSM_ESTABLISHED
```

0 files changed, 0 insertions, 0 deletions