Better handling of JQuery check

[soulgalore]

[2016-05-12 09:48:57] http://www.svensktnaringsliv.se generated the following errors in the coach {
  "performance": {
    "jquery": "Cannot read property 'jquery' of undefined"
  }
}

[2016-05-12 10:48:27] http://www.norrkoping.se generated the following errors in the coach {
  "performance": {
    "jquery": "window.jQuery.fn is undefined"
  }
}