message: log error in pass thread
diff: @@ -770,7 +770,7 @@ function Facebookbot(configuration) {
  };
  console.log({request_body})
  request.post('https://' + api_host + '/v2.6/me/pass_thread_control?access_token=' + configuration.access_token,
  - JSON.stringify(request_body),
  + request_body,
  function(err, res, body) {
  if (err) {
  facebook_botkit.log('Could not pass thread control');
  @@ -786,6 +786,7 @@ function Facebookbot(configuration) {
  if (results) {
  if (results.error) {
  facebook_botkit.log('ERROR in pass thread control API call: ', results.error.message);
  + cb && cb(results)
  } else {
  facebook_botkit.debug('Successfully pass thread control', body);
  cb && cb(result);
  