Update reference/constraints/map.rst.inc

Co-authored-by: Christian Flothmann <christian.flothmann@gmail.com>

Author: gitomato

reference/constraints/map.rst.inc

@@ -91,7 +91,7 @@ Financial and other Number Constraints
 * :doc:`Isin </reference/constraints/Isin>`
 
 Doctrine Constraints
-~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~
 
 * :doc:`UniqueEntity </reference/constraints/UniqueEntity>`
 * :doc:`EnableAutoMapping </reference/constraints/EnableAutoMapping>`