message: Add a quick sender check to isLastSuccessful
diff: @@ -604,6 +604,10 @@ export default class MessagePanel extends React.Component {
  isLastSuccessful = true;
  }
  + // We only want to consider "last successful" if the event is sent by us, otherwise of course
  + // it's successful: we received it.
  + isLastSuccessful = isLastSuccessful && mxEv.getSender() === MatrixClientPeg.get().getUserId();
  +
  // use txnId as key if available so that we don't remount during sending
  ret.push(
  <li
  