Use unicode for reference (is there any way to build this module)

Modules/xxmodule.c

@@ -246,7 +246,7 @@ static PyTypeObject Str_Type = {
 	0,			/*tp_methods*/
 	0,			/*tp_members*/
 	0,			/*tp_getset*/
-	&PyString_Type,		/*tp_base*/
+	&PyUnicode_Type,	/*tp_base*/
 	0,			/*tp_dict*/
 	0,			/*tp_descr_get*/
 	0,			/*tp_descr_set*/