readiness returns error quickly if any of the set is down (#9662)

This PR adds a new configuration parameter which allows readiness
check to respond within 10secs, this can be reduced to a lower value
if necessary using 

```
mc admin config set api ready_deadline=5s
```

 or

```
export MINIO_API_READY_DEADLINE=5s
```

cmd/peer-rest-common.go

@@ -54,6 +54,7 @@ const (
 	peerRESTMethodTrace                 = "/trace"
 	peerRESTMethodListen                = "/listen"
 	peerRESTMethodLog                   = "/log"
+	peerRESTMethodGetLocalDiskIDs       = "/getlocaldiskids"
 )
 
 const (