Revert "JS: Use an actual sanitizer in test"

This reverts commit 267157b255d9612dc5e8a8c6bb4f4d8138674909.

Author: asgerf

javascript/ql/test/query-tests/Security/CWE-601/ServerSideUrlRedirect/express.js

@@ -23,7 +23,7 @@ app.get('/some/other/path2', function(req, res) {
 
 app.get('/some/path', function(req, res) {
   var target = req.param("target");
-  if (target.startsWith("https://example.com/"))
+  if (isLocalURL(target))
     // OK - request parameter is sanitized before incorporating it into the redirect
     res.redirect(target);
   else