message: Remove v1 identity server fallbacks
  For
diff: @@ -181,7 +181,6 @@ export default class IdentityAuthClient {
  }
  async registerForToken(check=true) {
  - try {
  const hsOpenIdToken = await MatrixClientPeg.get().getOpenIdToken();
  // XXX: The spec is `token`, but we used `access_token` for a Sydent release.
  const { access_token: accessToken, token } =
  @@ -189,16 +188,5 @@ export default class IdentityAuthClient {
  const identityAccessToken = token ? token : accessToken;
  if (check) await this._checkToken(identityAccessToken);
  return identityAccessToken;
  - } catch (e) {
  - if (e.cors === "rejected" || e.httpStatus === 404) {
  - // Assume IS only supports deprecated v1 API for now
  - // TODO: Remove this path once v2 is only supported version
  - // See https://github.com/vector-im/riot-web/issues/10443
  - console.warn("IS doesn't support v2 auth");
  - this.authEnabled = false;
  - return;
  - }
  - throw e;
  - }
  }
  }
  