updated threaded contiki test scripts

tools/cooja/contiki_tests/sky_helloworld.js

@@ -1,7 +1,4 @@
-/* Script is called once for every node log output. */
-/* Input variables: Mote mote, int id, String msg. */
+TIMEOUT(2000, log.log("last message: " + msg + "\n"));
 
-if (msg.startsWith('Hello, world')) {
-  log.log('TEST OK\n'); /* Report test success */
-  mote.getSimulation().getGUI().doQuit(false); /* Quit simulator (to end test run)*/
-}
+WAIT_UNTIL(msg.equals('Hello, world'));
+log.testOK();