Issue #17047: remove doubled words added in 3.3
as reported by Serhiy Storchaka and Matthew Barnett.
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 69a2faf..e8256a5 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -4492,7 +4492,7 @@
             x = Decimal(2**578) ** Decimal("-0.5")
 
     def test_py_immutability_operations(self):
-        # Do operations and check that it didn't change change internal objects.
+        # Do operations and check that it didn't change internal objects.
         Decimal = P.Decimal
         DefaultContext = P.DefaultContext
         setcontext = P.setcontext