style: Typo in content title

Author: sevjan

testing/database.rst

@@ -89,7 +89,7 @@ the employee which gets returned by the ``Repository``, which itself gets
 returned by the ``EntityManager``. This way, no real class is involved in
 testing.
 
-Functional Testing of A Doctrine Repository
+Functional Testing of a Doctrine Repository
 -------------------------------------------
 
 In :ref:`functional tests <functional-tests>` you'll make queries to the