Fix chr() test (1000000 was accepted on a UCS4 build).
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 30cc37c..27ddf72 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -99,7 +99,7 @@
         except TypeError: pass
 
         self.raise_catch(ValueError, "ValueError")
-        self.assertRaises(ValueError, chr, 1000000)
+        self.assertRaises(ValueError, chr, sys.maxunicode+1)
 
         self.raise_catch(ZeroDivisionError, "ZeroDivisionError")
         try: x = 1/0