Update doctrine.rst

Author: hectorprats

reference/configuration/doctrine.rst

@@ -159,6 +159,7 @@ service where ``[name]`` is the name of the connection. Or directly in the contr
 getConnection method and the name of the connection.
 
 .. code-block:: php
+
     $conex = $this->getDoctrine()->getConnection('customer');
     $res = $conex->fetchAll('select * from table');