message: Remove id_server for MSISDN registration
  For HSes that no longer need it, remove the id_server param when verifying
  MSISDNs at registration.
  Fixes
diff: @@ -453,7 +453,7 @@ export const MsisdnAuthEntry = createReactClass({
  });
  },
  - _onFormSubmit: function(e) {
  + _onFormSubmit: async function(e) {
  e.preventDefault();
  if (this.state.token == '') return;
  @@ -461,37 +461,37 @@ export const MsisdnAuthEntry = createReactClass({
  errorText: null,
  });
  - this.props.matrixClient.submitMsisdnToken(
  + try {
  + const result = await this.props.matrixClient.submitMsisdnToken(
  this._sid, this.props.clientSecret, this.state.token,
  - ).then((result) => {
  + );
  if (result.success) {
  + const creds = {
  + sid: this._sid,
  + client_secret: this.props.clientSecret,
  + };
  + if (await this.props.matrixClient.doesServerRequireIdServerParam()) {
  const idServerParsedUrl = url.parse(
  this.props.matrixClient.getIdentityServerUrl(),
  );
  + creds.id_server = idServerParsedUrl.host;
  + }
  this.props.submitAuthDict({
  type: MsisdnAuthEntry.LOGIN_TYPE,
  // TODO: Remove `threepid_creds` once servers support proper UIA
  // See https://github.com/vector-im/riot-web/issues/10312
  - threepid_creds: {
  - sid: this._sid,
  - client_secret: this.props.clientSecret,
  - id_server: idServerParsedUrl.host,
  - },
  - threepidCreds: {
  - sid: this._sid,
  - client_secret: this.props.clientSecret,
  - id_server: idServerParsedUrl.host,
  - },
  + threepid_creds: creds,
  + threepidCreds: creds,
  });
  } else {
  this.setState({
  errorText: _t("Token incorrect"),
  });
  }
  - }).catch((e) => {
  + } catch (e) {
  this.props.fail(e);
  console.log("Failed to submit msisdn token");
  - }).done();
  + }
  },
  render: function() {
  