grammar in logging.rst

Fix typo: "due to retain" → "in order to retain"

"in order" is grammatically redundant, but it's to avoid having homophones "2" and "to" right next to each other.

Author: wjandrea

Doc/library/logging.rst

@@ -1317,7 +1317,7 @@ functions.
       In Python versions earlier than 3.4, this function could also be passed a
       text level, and would return the corresponding numeric value of the level.
       This undocumented behaviour was considered a mistake, and was removed in
-      Python 3.4, but reinstated in 3.4.2 due to retain backward compatibility.
+      Python 3.4, but reinstated in 3.4.2 in order to retain backward compatibility.
 
 .. function:: getHandlerByName(name)