[#7224] fix indentation

Author: xabbuh

best_practices/configuration.rst

@@ -186,9 +186,9 @@ through environment variables:
             password: "%env(DB_PASSWORD)%"
 
 .. versionadded:: 3.2
-   Support for runtime environment variables via the ``%env(...)%`` syntax was
-   added in Symfony 3.2. Prior to version 3.2, you needed to use the
-   :doc:`special SYMFONY__ variables </configuration/external_parameters>`.
+    Support for runtime environment variables via the ``%env(...)%`` syntax
+    was added in Symfony 3.2. Prior to version 3.2, you needed to use the
+    :doc:`special SYMFONY__ variables </configuration/external_parameters>`.
 
 .. _`feature toggles`: https://en.wikipedia.org/wiki/Feature_toggle
 .. _`constant() function`: http://twig.sensiolabs.org/doc/functions/constant.html