message: fix vsc++ compile error
diff: @@ -819,7 +819,7 @@ void wamp_session::handle_HELLO(json_array& ja)
  std::string authrole = WAMP_ANONYMOUS;
  - if (m_auth_proivder.user_role and m_authid.first) {
  + if (m_auth_proivder.user_role && m_authid.first) {
  authrole = m_auth_proivder.user_role(m_authid.second, m_realm);
  if(authrole.empty())
  throw auth_error(WAMP_ERROR_NO_SUCH_ROLE, "role not configured");
  