fix test_py3kwarns

The fact that this was failing and went unnoticed so long seems like a good argument for being able to enable and disble py3kwarnings through Python.
diff --git a/Lib/plat-mac/ic.py b/Lib/plat-mac/ic.py
index beb8226..8337f2d 100644
--- a/Lib/plat-mac/ic.py
+++ b/Lib/plat-mac/ic.py
@@ -1,7 +1,7 @@
 """IC wrapper module, based on Internet Config 1.3"""
 
 from warnings import warnpy3k
-warnpy3k("In 3.x, the ic module is removed.")
+warnpy3k("In 3.x, the ic module is removed.", stacklevel=2)
 
 import icglue
 import string