Fix scale metrics when there is no processors information

... ],  
"processors": [],  // No processors information
"metrics": [    
{      "timestamp": 1710942380,
...

{
  "scale": {
    "currentNodes": 1,
    "bestNodes": 2147483647,         // infinity of nodes (MAX_INT)
    "metric": 2147483646
  },
  "nodes": [],
  "computations": [
    {
      "computation": "bulk-XXX",
      "streams": {...},
      "nodes": [
        {
          "nodeId": "worker-1",
          "threads": null,            // we don't know the number of threads because we lost the processor information
          "timestamp": 1710942565,
          "count": 26346,
          ...      
        }      ],
      "current": {
        "nodes": 1,
        "threads": 0,
        "rate1m": 0.00042257344,
        "eta": 18562454
      },
      "best": {
        "nodes": 2147483647,
        "threads": 1,
        "rate1m": "Infinity",
        "eta": 0
      }
    }
  ]
}