Quiten boto logging in func tests

Some s3api functional tests were setting boto logging level to DEBUG,
which results in a very large amount of logging output from the test
runner, including large request bodies. This makes it extremely hard
to inspect test output.

This patch makes the quiet_boto_logging context manager revert the
logger level to its original value rather than indiscriminately
leaving it set to DEBUG.

Change-Id: I1dd9603adf9a19e89da5a461d3c6810a3432ae46

test/functional/s3api/__init__.py

@@ -45,11 +45,12 @@ class S3ApiBase(unittest.TestCase):
 
     @contextmanager
     def quiet_boto_logging(self):
+        original_level = logging.getLogger('boto').getEffectiveLevel()
         try:
             logging.getLogger('boto').setLevel(logging.INFO)
             yield
         finally:
-            logging.getLogger('boto').setLevel(logging.DEBUG)
+            logging.getLogger('boto').setLevel(original_level)
 
     def setUp(self):
         if not tf.config.get('s3_access_key'):