bgpd: Show pfxSnt in JSON output for show bgp summary even if not established

bgpd: Show pfxSnt in JSON output for show bgp summary even if not established

spine1-debian-9# show ip bgp summary json
{
"ipv4Unicast":{
  "routerId":"192.168.3.2",
  "as":200,
  "vrfId":0,
  "vrfName":"default",
  "tableVersion":4,
  "ribCount":1,
  "ribMemory":184,
  "peerCount":1,
  "peerMemory":23384,
  "peers":{
    "192.168.0.1":{
      "hostname":"exit1-debian-9",
      "remoteAs":100,
      "version":4,
      "msgRcvd":5,
      "msgSent":6,
      "tableVersion":0,
      "outq":0,
      "inq":0,
      "peerUptime":"00:00:09",
      "peerUptimeMsec":9000,
      "peerUptimeEstablishedEpoch":1606206209,
      "pfxRcd":0,
      "pfxSnt":0,
      "state":"Idle (Admin)",
      "connectionsEstablished":1,
      "connectionsDropped":1,
      "idType":"ipv4"
    }
  },
  "failedPeers":1,
  "totalPeers":1,
  "dynamicPeers":0,
  "bestPath":{
    "multiPathRelax":"false"
  }
}
}

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>