Missing jsonc comments from generated JSON

[sveinse]

odg now omits comments on certain variable in JSON format. This used to work in odg3.4 and are not working in odg3.5

    {
      "index": "0x1003",  // 4099
      "name": "Pre-defined Error Field",
      "struct": "array",
      "group": "built-in",
      "mandatory": false,
      "profile_callback": true,
      "each": {
        "name": "Standard Error Field",
        "type": "UNSIGNED32",  // 7   <-- This is missing in odg3.5
        "access": "ro",
        "pdo": false,
        "nbmin": 1,
        "nbmax": 254
      },
    }