Update imports in Lib/test/test_sax.py

Co-authored-by: Sebastian Pipping <sebastian@pipping.org>

Author: ukarroum

Lib/test/test_sax.py

@@ -1,6 +1,7 @@
 # regression test for SAX 2.0
 from xml.sax import make_parser, ContentHandler, \
-                    SAXException, SAXReaderNotAvailable, SAXParseException, handler
+                    SAXException, SAXReaderNotAvailable, SAXParseException
+from xml.sax.handler import feature_namespaces, feature_namespace_prefixes
 import unittest
 from unittest import mock
 try: