Don't remove traceback on rethrow

Author: slozier

Diff for: Src/IronPython/Runtime/Operations/PythonOps.cs

@@ -2176,12 +2176,7 @@ public static PythonTuple GetExceptionInfo(CodeContext/*!*/ context) {
         /// </summary>
         public static Exception MakeRethrownException(CodeContext/*!*/ context) {
             PythonTuple t = GetExceptionInfo(context);
-
-            Exception e = MakeExceptionWorker(context, t[0], t[1], t[2], null, true);
-
-            e.RemoveTraceBack();
-            ExceptionHelpers.UpdateForRethrow(e);
-            return e;
+            return MakeExceptionWorker(context, t[0], t[1], t[2], null, true);
         }
 
         /// <summary>