Rika notifications json message issue (latest channel)

[sebastienvermeille]

impact: latest (not any released version)

While testing rika notifications,
I discovered that the serialized json message is like that:

{
  "stoveId": {
    "id": 42
  },
  "errorCode": "E0001.02"
}

instead of expected:

{
  "stoveId":  42,
  "errorCode": "E0001.02"
}