message: don't try to get id server domain when not asked to bind
diff: @@ -20,6 +20,10 @@ import MatrixClientPeg from './MatrixClientPeg';
  import { _t } from './languageHandler';
  import IdentityAuthClient from './IdentityAuthClient';
  +function getIdServerDomain() {
  + return MatrixClientPeg.get().idBaseUrl.split("://")[1];
  +}
  +
  /**
  * Allows a user to add a third party identifier to their homeserver and,
  * optionally, the identity servers.
  @@ -155,7 +159,6 @@ export default class AddThreepid {
  * the request failed.
  */
  async checkEmailLinkClicked() {
  - const identityServerDomain = MatrixClientPeg.get().idBaseUrl.split("://")[1];
  try {
  if (await MatrixClientPeg.get().doesServerSupportSeparateAddAndBind()) {
  if (this.bind) {
  @@ -164,7 +167,7 @@ export default class AddThreepid {
  await MatrixClientPeg.get().bindThreePid({
  sid: this.sessionId,
  client_secret: this.clientSecret,
  - id_server: identityServerDomain,
  + id_server: getIdServerDomain(),
  id_access_token: identityAccessToken,
  });
  } else {
  @@ -177,7 +180,7 @@ export default class AddThreepid {
  await MatrixClientPeg.get().addThreePid({
  sid: this.sessionId,
  client_secret: this.clientSecret,
  - id_server: identityServerDomain,
  + id_server: getIdServerDomain(),
  }, this.bind);
  }
  } catch (err) {
  