'exists' returns an error

[simoami]

api/cards/{id}/exists

returns a 200 response if the element was found with:
{ "exists": true }

otherwise it returns a 404 error:

{
  "error": {
    "name": "Error",
    "status": 404,
    "message": "Unknown \"card\" id \"2\".",
    "statusCode": 404,
    "stack": "Error: Unknown \"card\" id \"2\".\n    at Function.setRemoting.rest.after ...."
  }
}

The proper behavior when the object is not found is to return a 200 response with:
{ "exists": false }

otherwise there is no point in reading the returned attribute.

[superkhau]

reproducible, reporting as a bug

[superkhau]

Fixed in #681

[simoami]

Thanks for the update!