message: fix error when initiating handover protocol
diff: @@ -352,7 +352,7 @@ export class FacebookAdapter extends BotAdapter {
  // handle standby messages (this bot is not the active receiver)
  if (entry.standby) {
  - payload = entry.standyby;
  + payload = entry.standby;
  for (let m = 0; m < payload.length; m++) {
  let message = payload[m];
  