use threading in testserver and ivrd

libs/esl/src/include/esl.h

@@ -391,7 +391,7 @@ ESL_DECLARE(esl_status_t) esl_attach_handle(esl_handle_t *handle, esl_socket_t s
     \param port Port to bind to
     \param callback Callback that will be called upon data received
 */
-ESL_DECLARE(esl_status_t) esl_listen(const char *host, esl_port_t port, esl_listen_callback_t callback);
+ESL_DECLARE(esl_status_t) esl_listen(const char *host, esl_port_t port, esl_listen_callback_t callback, int max);
 /*!
     \brief Executes application with sendmsg to a specific UUID. Used for outbound socket.
     \param handle Handle that the msg will be sent