Missing comma in YML configuration example

Author: jdhoek

cookbook/request/mime_type.rst

@@ -70,7 +70,7 @@ file and register it as a listener by adding the ``kernel.listener`` tag:
  acme.demobundle.listener.request:
  class: Acme\DemoBundle\RequestListener
  tags:
- - { name: kernel.listener event: onCoreRequest }
+ - { name: kernel.listener, event: onCoreRequest }
 
  .. code-block:: php