warnings.catch_warnings() now returns a list or None instead of the custom
WarningsRecorder object. This makes the API simpler to use as no special object
must be learned.

Closes issue 3781.
Review by Benjamin Peterson.
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 1dcbbed..7b351b8 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -641,7 +641,7 @@
 
 def test_main():
     import warnings
-    with test_support.catch_warning(record=False):
+    with warnings.catch_warnings():
         warnings.filterwarnings('ignore', ".*urllib\.urlopen.*Python 3.0",
                                 DeprecationWarning)
         test_support.run_unittest(