FS-3002: handle 2833 in do_flush instead of dropping valid dtmf

src/switch_apr.c

@@ -833,7 +833,7 @@ SWITCH_DECLARE(switch_status_t) switch_socket_recvfrom(switch_sockaddr_t *from,
 		 */
 	}
 
-	if (r == 35) {
+	if (r == 35 || r == 730035) {
 		r = SWITCH_STATUS_BREAK;
 	}