Fix for websockets regression.

src/loop.c

@@ -601,7 +601,12 @@ int mosquitto_main_loop(struct mosquitto_db *db, mosq_sock_t *listensock, int li
 			 * will soon, so for now websockets clients are second class
 			 * citizens. */
 			if(db->config->listeners[i].ws_context){
+#if LWS_LIBRARY_VERSION_NUMBER > 3002000
 				libwebsocket_service(db->config->listeners[i].ws_context, -1);
+#else
+				libwebsocket_service(db->config->listeners[i].ws_context, 0);
+#endif
+
 			}
 		}
 		if(db->config->have_websockets_listener){