message: fix(client): don't crash on extension message events
diff: @@ -19,6 +19,10 @@ export default createPromiseThunkAction(
  const state = getState();
  window.addEventListener("message", envelope => {
  + if (typeof envelope.data !== "string") {
  + return;
  + }
  +
  if (envelope.data.indexOf("[iFrameSizer]") === 0) {
  return;
  }
  