Update service_container/factories.rst

Author: OskarStark

service_container/factories.rst

@@ -151,10 +151,7 @@ called to create its object. In this case we don't need a dedicated factory clas
 
             <services>
                 <service id="App\Email\NewsletterManager">
-                    <!-- Note that we are using the "class" key here, not "service" -->
-                    <factory class="App\Email\NewsletterManager"
-                        method="create"
-                    />
+                    <factory method="create"/>
                 </service>
             </services>
         </container>