message: update immediately, don't wait until verification is done
  this can deadlock, as you can't finish the verification without the UI
diff: @@ -217,9 +217,12 @@ export default class VerificationPanel extends React.PureComponent {
  };
  _onRequestChange = async () => {
  + this.forceUpdate();
  const {request} = this.props;
  - if (!this._hasVerifier && !!request.verifier) {
  - request.verifier.on('show_sas', this._onVerifierShowSas);
  + const hadVerifier = this._hasVerifier;
  + this._hasVerifier = !!request.verifier;
  + if (!hadVerifier && this._hasVerifier) {
  + request.verifier.once('show_sas', this._onVerifierShowSas);
  try {
  // on the requester side, this is also awaited in _startSAS,
  // but that's ok as verify should return the same promise.
  @@ -227,10 +230,7 @@ export default class VerificationPanel extends React.PureComponent {
  } catch (err) {
  console.error("error verify", err);
  }
  - } else if (this._hasVerifier && !request.verifier) {
  - request.verifier.removeListener('show_sas', this._onVerifierShowSas);
  }
  - this._hasVerifier = !!request.verifier;
  };
  componentDidMount() {
  