Fix the ip address in browser_args

On mac using 127.0.0.254 doesn't seem to work, whereas 127.0.0.1 does
work in the way this test intends it to work.

Author: ankur22

examples/browser_args.js

@@ -10,7 +10,7 @@ export const options = {
 export default function() {
   const browser = chromium.launch({
     headless: __ENV.XK6_HEADLESS ? true : false,
-    args: ['host-resolver-rules=MAP test.k6.io 127.0.0.254'],
+    args: ['host-resolver-rules=MAP test.k6.io 127.0.0.1'],
   });
   const context = browser.newContext();
   const page = context.newPage();