[*] TR : update English translations key for Back Office

git-svn-id: http://dev.prestashop.com/svn/v1/branches/1.5.x@16369 b9a71923-0436-4b27-9f14-aed3839534dd

controllers/admin/AdminOrderPreferencesController.php

@@ -75,7 +75,7 @@ class AdminOrderPreferencesControllerCore extends AdminController
 					),
 					'PS_GUEST_CHECKOUT_ENABLED' => array(
 						'title' => $this->l('Enable guest checkout'),
-						'desc' => $this->l('Guest can place an order without registering'),
+						'desc' => $this->l('Guests can place an order without registering'),
 						'validation' => 'isBool',
 						'cast' => 'intval',
 						'type' => 'bool'