Fixed outdated json definition

[gmessow-cxomni]

According to the Usabilla API documentation a campaign result looks like this:

{
  "id": "549972d5c469885e548b4570",
  "campaignId": "5499612ec4698839368b4573",
  "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36",
  "location": "Amsterdam, Netherlands",
  "date": "2014-01-15T19:48:06.003Z",
  "customData": {
    "form_name": "form1"
  },
  "data": {
    "text": "test"
  },
  "time": 5000,
  "url": "https://usabilla.com"
}

However CampaignResultStruct had an outdated json definition and I fixed it.