--starter.port of "leader" starter not persisted across restarts

[dothebart]

launch a cluster with these --starter.port's :

9528
9628
9728

and stop all instances.
go into the respective directories, and re-launch the starter without any parameters again. The cluster will now bind:

tcp6       0      0 :::8528                 :::*                    LISTEN      378399/arangodb     
tcp6       0      0 :::9529                 :::*                    LISTEN      378598/arangod      
tcp6       0      0 :::9530                 :::*                    LISTEN      378588/arangod      
tcp6       0      0 :::9531                 :::*                    LISTEN      378422/arangod      
tcp6       0      0 :::9629                 :::*                    LISTEN      378801/arangod      
tcp6       0      0 :::9630                 :::*                    LISTEN      378790/arangod      
tcp6       0      0 :::9631                 :::*                    LISTEN      378634/arangod      
tcp6       0      0 :::9729                 :::*                    LISTEN      379007/arangod      
tcp6       0      0 :::9730                 :::*                    LISTEN      378997/arangod      
tcp6       0      0 :::9731                 :::*                    LISTEN      378843/arangod      

So, starter instance 1 will not bind port 9528 but port 8528 instead.

Starter instance 2 & 3 will continue to groan about not being able to connect the first starter:

2020-10-05T16:42:32+02:00 |WARN| Failed to load cluster configuration from http://localhost:9528/ component=arangodb error="Get http://localhost:9528/hello?update=1: dial tcp [::1]:9528: connect: connection refused"

The processes will re-launch and work as expected.

This happenes, though the setup.json contains the proper port to bind:

{
  "version": "0.2.2",
  "id": "98c52ca1",
  "peers": {
    "Peers": [
      {
        "ID": "98c52ca1",
        "Address": "localhost",
        "Port": 9528,
        "PortOffset": 0,
        "DataDir": "/tmp/CLUSTER/node1",
        "HasAgent": true,
        "IsSecure": false
      },