message: remove link to issue
  not very useful
diff: @@ -504,7 +504,7 @@ var TimelinePanel = React.createClass({
  // very possible have logged out within that timeframe, so check
  // we still have a client.
  const cli = MatrixClientPeg.get();
  - // if no client or client is guest don't send RR (vector-im/riot-web#3758)
  + // if no client or client is guest don't send RR
  if (!cli || cli.isGuest()) return;
  var currentReadUpToEventId = this._getCurrentReadReceipt(true);
  