replace PyXXX_Length calls with PyXXX_Size calls
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index f4b90e8..ab44e91 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -759,7 +759,7 @@
 	/* From here on out, errors go through finally: for proper
 	 * reference count manipulations.
 	 */
-	seqlen = PySequence_Length(seq);
+	seqlen = PySequence_Size(seq);
 	if (seqlen == 1) {
 		item = PySequence_Fast_GET_ITEM(seq, 0);
 		Py_INCREF(item);