Update userguide controller for $response->check_cache() changes. Refs #4373

Author: kiall

classes/controller/userguide.php

@@ -258,7 +258,7 @@ public function action_media()
 		if ($file = Kohana::find_file('media/guide', $file, $ext))
 		{
 			// Check if the browser sent an "if-none-match: <etag>" header, and tell if the file hasn't changed
-			$this->response->check_cache(sha1($this->request->uri()).filemtime($file), $this->request);
+			$this->check_cache(sha1($this->request->uri()).filemtime($file));
 
 			// Send the file content as the response
 			$this->response->body(file_get_contents($file));