docs: fix incorrect sample

By default, 'App\Controllers\Galleries::showUserGallery/$1/$2' means 'App\Controllers\App\Controllers\Galleries::showUserGallery/$1/$2'.

Author: kenjis

user_guide_src/source/incoming/routing/029.php

@@ -1,10 +1,10 @@
 <?php
 
 // The route is defined as:
-$routes->get('users/(:num)/gallery(:any)', 'App\Controllers\Galleries::showUserGallery/$1/$2');
+$routes->get('users/(:num)/gallery(:any)', 'Galleries::showUserGallery/$1/$2');
 
 ?>
 
 <!-- Generate the relative URL to link to user ID 15, gallery 12: -->
-<a href="<?= route_to('App\Controllers\Galleries::showUserGallery', 15, 12) ?>">View Gallery</a>
+<a href="<?= route_to('Galleries::showUserGallery', 15, 12) ?>">View Gallery</a>
 <!-- Result: '/users/15/gallery/12' -->