minor #4835 Fixed broken link (SofHad)

This PR was merged into the 2.3 branch.

Discussion
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Fixed broken link

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | #4827

Commits
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05d1a64 Fixed broken link #4827

reference/dic_tags.rst

@@ -618,7 +618,7 @@ kernel.terminate
 +-------------------------------------------------------------------------------------------+----------+
 | Listener Class Name                                                                       | Priority |
 +===========================================================================================+==========+
-| :class:`Symfony\\Bundle\\SwiftmailerBundle\\EventListener\\EmailSenderListener`           | 0        |
+| `EmailSenderListener`_                                                                    | 0        |
 +-------------------------------------------------------------------------------------------+----------+
 
 .. _dic-tags-kernel-event-subscriber:
@@ -1396,3 +1396,4 @@ For an example, see the ``EntityInitializer`` class inside the Doctrine Bridge.
 .. _`Twig official extension repository`: https://github.com/twigphp/Twig-extensions
 .. _`SwiftMailer's Plugin Documentation`: http://swiftmailer.org/docs/plugins.html
 .. _`Twig Loader`: http://twig.sensiolabs.org/doc/api.html#loaders
+.. _`EmailSenderListener`: https://github.com/symfony/SwiftmailerBundle/blob/master/EventListener/EmailSenderListener.php