bug #5202 added missing tab (martinbertinat)

This PR was submitted for the 2.6 branch but it was merged into the 2.3 branch instead (closes #5202).

Discussion
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added missing tab

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.6,2.7
| Fixed tickets |

Commits
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f7c84ca added missing tab

Author: wouterj

cookbook/serializer.rst

@@ -77,7 +77,7 @@ Here is an example on how to load the
         # app/config/services.yml
         services:
             get_set_method_normalizer:
-            class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
+                class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
                 tags:
                     - { name: serializer.normalizer }