Fix a minor syntax issue

Author: javiereguiluz

security/voters.rst

@@ -269,11 +269,11 @@ with ``ROLE_SUPER_ADMIN``::
             // ...
         }
 
-        The ``Security::isGranted()`` method inside a voter has a significant
-        drawback: it does not guarantee that the checks are performed on the same
-        token as the one in your voter. The token in the token storage might have
-        changed or could change in the meantime. Always use the ``AccessDecisionManager``
-        instead.
+    The ``Security::isGranted()`` method inside a voter has a significant
+    drawback: it does not guarantee that the checks are performed on the same
+    token as the one in your voter. The token in the token storage might have
+    changed or could change in the meantime. Always use the ``AccessDecisionManager``
+    instead.
 
 If you're using the :ref:`default services.yaml configuration <service-container-services-load-example>`,
 you're done! Symfony will automatically pass the ``security.helper``