message: Send MSISDN validation token to submit_url during registration
  Similar to previous changes for 3PID add, this changes registration with MSISDN
  to also send tokens to `submit_url` when supplied.
  Fixes
diff: @@ -420,6 +420,7 @@ export const MsisdnAuthEntry = createReactClass({
  },
  componentWillMount: function() {
  + this._submitUrl = null;
  this._sid = null;
  this._msisdn = null;
  this._tokenBox = null;
  @@ -442,6 +443,7 @@ export const MsisdnAuthEntry = createReactClass({
  this.props.clientSecret,
  1, // TODO: Multiple send attempts?
  ).then((result) => {
  + this._submitUrl = result.submit_url;
  this._sid = result.sid;
  this._msisdn = result.msisdn;
  });
  @@ -462,9 +464,16 @@ export const MsisdnAuthEntry = createReactClass({
  });
  try {
  - const result = await this.props.matrixClient.submitMsisdnToken(
  + let result;
  + if (this._submitUrl) {
  + result = await this.props.matrixClient.submitMsisdnTokenOtherUrl(
  + this._submitUrl, this._sid, this.props.clientSecret, this.state.token,
  + );
  + } else {
  + result = await this.props.matrixClient.submitMsisdnToken(
  this._sid, this.props.clientSecret, this.state.token,
  );
  + }
  if (result.success) {
  const creds = {
  sid: this._sid,
  