refactor: use cached slice in app.listen (#6897)

Signed-off-by: Tacit1 <tacitim5@gmail.com>

lib/application.js

@@ -597,7 +597,7 @@ app.render = function render(name, options, callback) {
 
 app.listen = function listen() {
   var server = http.createServer(this)
-  var args = Array.prototype.slice.call(arguments)
+  var args = slice.call(arguments)
   if (typeof args[args.length - 1] === 'function') {
     var done = args[args.length - 1] = once(args[args.length - 1])
     server.once('error', done)