code: public FessMessages addErrorsSsoLoginError(String property) {
          assertPropertyNotNull(property);
          add(property, new UserMessage(ERRORS_sso_login_error));
          return this;
      }
docs: Add the created action message for the key 'errors.sso_login_error' with parameters.
  <pre>
  message: Failed to process SSO login.
  </pre>
  @param property The property name for the message. (NotNull)
  @return this. (NotNull)