unused, just display downstream config

Example request

{
  "concurrentThreads": 5,
  "ip": "127.0.0.1",
  "maxTxnRow": 4,
  "password": "my_password",
  "port": 4534,
  "targetClusterId": "CLUSTER_ID_IN_TIUNIMANAGER__22",
  "username": "tidb",
  "workerCount": 2
}