swarm metrics: connection counting seems broken

[marten-seemann]

While at the same time:

❯ ipfs swarm peers | wc
   1487    1487  135713

config:

  "Swarm": {
    "AddrFilters": null,
    "ConnMgr": {
      "GracePeriod": "20s",
      "HighWater": 1500,
      "LowWater": 900,
      "Type": "basic"
    },

[sukunrt]

Do you have a long running node?
On my setup the primary source of divergence is MetricsTracer.ClosedConnection not being called when two dials succeed and one of them is dropped here

We can just call MetricsTracer.ClosedConnection there or we can move the OpenedConnection call to swarm.addConn