[ticket/17176] Use Symfony name for event dispatcher

The previously used override of the names is no longer supported.

PHPBB3-17176

phpBB/config/default/container/services_http.yml

@@ -2,7 +2,7 @@ services:
     http_kernel:
         class: Symfony\Component\HttpKernel\HttpKernel
         arguments:
-            - '@dispatcher'
+            - '@event_dispatcher'
             - '@controller.resolver'
             - '@request_stack'