Clarify version number in logging.rst

3.4 technically includes 3.4.2, so put 3.4.0 to clarify.

Author: wjandrea

Doc/library/logging.rst

@@ -1314,10 +1314,10 @@ functions.
       vice versa.
 
    .. versionchanged:: 3.4
-      In Python versions earlier than 3.4, this function could also be passed a
+      In Python versions earlier than 3.4.0, 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 in order to retain backward compatibility.
+      Python 3.4.0, but reinstated in 3.4.2 in order to retain backward compatibility.
 
 .. function:: getHandlerByName(name)