Ergänze Service-Id für Symfony 4-Kompatibilität (Case 107508)

Author: Malte Wunsch

NotModified/services.xml

@@ -4,7 +4,7 @@
            xmlns="http://symfony.com/schema/dic/services"
            xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
     <services>
-        <service class="Webfactory\HttpCacheBundle\NotModified\EventListener" public="true">
+        <service id="Webfactory\HttpCacheBundle\NotModified\EventListener" class="Webfactory\HttpCacheBundle\NotModified\EventListener" public="true">
             <argument type="service" id="annotation_reader" />
             <argument type="service" id="service_container" />
             <tag name="kernel.event_listener" event="kernel.controller" priority="-200" />