Merge pull request #165 from php-http/Nyholm-patch-33

We need the concrete implementation, not the interface.

Author: Nyholm

DependencyInjection/HttplugExtension.php

@@ -19,7 +19,6 @@
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ChildDefinition;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\DefinitionDecorator;
 use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
@@ -149,7 +148,7 @@ private function configureSharedPlugins(ContainerBuilder $container, array $conf
      * @param ContainerBuilder $container  In case we need to add additional services for this plugin
      * @param string           $serviceId  Service id of the plugin, in case we need to add additional services for this plugin.
      */
-    private function configurePluginByName($name, Definition $definition, array $config, ContainerInterface $container, $serviceId)
+    private function configurePluginByName($name, Definition $definition, array $config, ContainerBuilder $container, $serviceId)
     {
         switch ($name) {
             case 'cache':