no nrpe check when members are out of sync

[Joe Guo]

In one of our clouds, a mongodb member was out of sync since April 2019.
We need a nrpe check to detect this.

myset:RECOVERING> rs.status()
{
    "set" : "myset",
    "date" : ISODate("2020-08-18T05:05:33Z"),
    "myState" : 3,
    "members" : [
        {
            "_id" : 0,
            "name" : "10.101.52.8:27017",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 15071152,
            "optime" : Timestamp(1597727090, 2169),
            "optimeDate" : ISODate("2020-08-18T05:04:50Z"),
            "lastHeartbeat" : ISODate("2020-08-18T05:05:31Z"),
            "lastHeartbeatRecv" : ISODate("2020-08-18T05:05:33Z"),
            "pingMs" : 0,
            "syncingTo" : "10.101.52.22:27017"
        },
        {
            "_id" : 1,
            "name" : "10.101.52.32:27017",
            "health" : 1,
            "state" : 3,
            "stateStr" : "RECOVERING",
            "uptime" : 17838930,
            "optime" : Timestamp(1556398523, 1),
            "optimeDate" : ISODate("2019-04-27T20:55:23Z"),
            "errmsg" : "still syncing, not yet to minValid optime 5f2dbb39:ed",
            "self" : true
        },
        {
            "_id" : 2,
            "name" : "10.101.52.22:27017",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 15070966,
            "optime" : Timestamp(1597727090, 2169),
            "optimeDate" : ISODate("2020-08-18T05:04:50Z"),
            "lastHeartbeat" : ISODate("2020-08-18T05:05:31Z"),
            "lastHeartbeatRecv" : ISODate("2020-08-18T05:05:33Z"),
            "pingMs" : 0,
            "syncingTo" : "10.101.52.8:27017"
        }
    ],
    "ok" : 1
}