minor #11153 use :: instead of .. code-block:: php (OskarStark)

This PR was merged into the 3.4 branch.

Discussion
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use :: instead of .. code-block:: php

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Commits
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60eeca0 use :: instead of .. code-block:: php

Author: javiereguiluz

components/options_resolver.rst

@@ -85,10 +85,8 @@ options are buried in the business logic of your code. Use the
         }
     }
 
-Now all four options are guaranteed to be set. But what happens if the user of
-the ``Mailer`` class makes a mistake?
-
-.. code-block:: php
+Now all four options are guaranteed to be set. Consider the user of the
+``Mailer`` class makes a mistake::
 
     $mailer = new Mailer([
         'usernme' => 'johndoe',  // usernme misspelled (instead of username)