Update profiler.rst

the getKernel() method is available in $event rather than $this.
Perhaps a full event subscriber class could be included to make it more complete?

Author: erickr

profiler.rst

@@ -195,7 +195,7 @@ event::
 
     public function onKernelResponse(ResponseEvent $event)
     {
-        if (!$this->getKernel()->isDebug()) {
+        if (!$event->getKernel()->isDebug()) {
             return;
         }