message: pass messages without payload
diff: @@ -134,6 +134,9 @@ browser.runtime.onConnect.addListener(function(m) {
  });
  browser.runtime.onMessageExternal.addListener((message, sender, sendResponse) => {
  + if (!message.payload) {
  + message.payload = {};
  + }
  message.payload.sender = sender.id;
  browser.runtime.sendMessage(message).then(sendResponse).catch(() => {
  return sendResponse({ error: "Selenium IDE is not active" });
  