Merge branch '5.1'

* 5.1:
  Reword
  Improve doc about log channel and env

Author: javiereguiluz

logging/channels_handlers.rst

@@ -25,7 +25,9 @@ Switching a Channel to a different Handler
 
 Now, suppose you want to log the ``security`` channel to a different file.
 To do this, create a new handler and configure it to log only messages
-from the ``security`` channel:
+from the ``security`` channel. The following example does that only in the
+``prod`` :ref:`configuration environment <configuration-environments>` but you
+can do it in any (or all) environments:
 
 .. configuration-block::