Missing information about payload in callback

Author: alamirault

reference/constraints/Callback.rst

@@ -304,11 +304,12 @@ callback method:
 * A closure.
 
 Concrete callbacks receive an :class:`Symfony\\Component\\Validator\\Context\\ExecutionContextInterface`
-instance as only argument.
+instance as the first argument and the :ref:`payload option <payload>` as the second argument.
 
 Static or closure callbacks receive the validated object as the first argument
-and the :class:`Symfony\\Component\\Validator\\Context\\ExecutionContextInterface`
-instance as the second argument.
+, the :class:`Symfony\\Component\\Validator\\Context\\ExecutionContextInterface`
+instance as the second argument and the :ref:`payload option <payload>` as the
+third argument.
 
 .. include:: /reference/constraints/_groups-option.rst.inc