Update XHProfMiddleware.php

Fix - first request after enabling xhprof did not get profiled

src/Middleware/XHProfMiddleware.php

@@ -28,7 +28,7 @@ public function handle(Request $request, Closure $next)
 
  //if profiler is enabled in config, don't wait for ?_profile=1 get parameter (which sets the cookie)
  //to start profiling, just enable it immediately
- setcookie('_profile', 1);
+ $_COOKIE['_profile'] = 1;
 
  require_once public_path(). '/vendor/xhprof/external/header.php';
  }