Replace bespoke NullHandler with Python's impl (boto#3510)

Author: nateprewitt

botocore/__init__.py

@@ -15,15 +15,11 @@
 import logging
 import os
 import re
+from logging import NullHandler
 
 __version__ = '1.39.4'
 
 
-class NullHandler(logging.Handler):
-    def emit(self, record):
-        pass
-
-
 # Configure default logger to do nothing
 log = logging.getLogger('botocore')
 log.addHandler(NullHandler())