send_bytes_per_sec in /rpcz json stats can be negative

        {
            "remote_ip": "10.196.10.165:27000",
            "num_calls_in_flight": 0,
            "outbound_queue_size": 0,
            "socket_stats": {
                "rtt": 91,
                "rttvar": 9,
                "snd_cwnd": 10,
                "total_retrans": 0,
                "pacing_rate": 4294967295,
                "max_pacing_rate": 4294967295,
                "bytes_acked": 7995867431,
                "bytes_received": 17908351,
                "segs_out": 1186603,
                "segs_in": 927339,
                "send_queue_bytes": 0,
                "receive_queue_bytes": 0,
                "send_bytes_per_sec": -694198066
            },
            "calls_in_flight": []
        },