replace API link for SwiftmailerBundle

Author: xabbuh

components/http_kernel/introduction.rst

@@ -495,10 +495,9 @@ as possible to the client (e.g. sending emails).
 
 .. sidebar:: ``kernel.terminate`` in the Symfony Framework
 
-    If you use the SwiftmailerBundle with Symfony and use ``memory``
-    spooling, then the :class:`Symfony\\Bundle\\SwiftmailerBundle\\EventListener\\EmailSenderListener`
-    is activated, which actually delivers any emails that you scheduled to
-    send during the request.
+    If you use the SwiftmailerBundle with Symfony and use ``memory`` spooling,
+    then the `EmailSenderListener`_ is activated, which actually delivers
+    any emails that you scheduled to send during the request.
 
 .. _component-http-kernel-kernel-exception:
 
@@ -709,3 +708,4 @@ look like this::
 .. _`SensioFrameworkExtraBundle`: http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/index.html
 .. _`@ParamConverter`: http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/annotations/converters.html
 .. _`@Template`: http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/annotations/view.html
+.. _`EmailSenderListener`: https://github.com/symfony/SwiftmailerBundle/blob/master/EventListener/EmailSenderListener.php