fixed incorrect reference to set*Service() method

src/Symfony/Component/DependencyInjection/Container.php

@@ -218,8 +218,8 @@ class Container implements ContainerInterface
     /**
      * Gets a service.
      *
-     * If a service is both defined through a set() method and
-     * with a set*Service() method, the former has always precedence.
+     * If a service is defined both through a set() method and
+     * with a get{$id}Service() method, the former has always precedence.
      *
      * @param string  $id              The service identifier
      * @param integer $invalidBehavior The behavior when the service does not exist