minor #1383 fix typo in doc (morontt)

This PR was merged into the 2.0.x-dev branch.

Discussion
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fix typo in doc

Replace Serializer Component to Security CSRF Component in documentation

Commits
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e3bb2141 fix typo in doc

doc/providers/csrf.rst

@@ -29,8 +29,8 @@ Registering
 
 .. note::
 
-    Add the Symfony's `Serializer Component
-    <http://symfony.com/doc/current/components/serializer.html>`_ as a
+    Add the Symfony's `Security CSRF Component
+    <http://symfony.com/doc/current/components/security/index.html>`_ as a
     dependency:
 
     .. code-block:: bash