Fix service id

JhonnyL · weaverryan · commit cf31894e8854 · 2015-03-14T14:30:00.000-04:00
diff --git a/cookbook/controller/service.rst b/cookbook/controller/service.rst
@@ -124,7 +124,7 @@ the route ``_controller`` value:
 
 .. versionadded:: 2.6
     If your controller service implements the ``__invoke`` method, you can simply refer to the service id
-    (``acme.hello.controller``).
+    (``app.hello_controller``).
 
 Alternatives to base Controller Methods
 ---------------------------------------
