fix

Author: corona10

Objects/listobject.c

@@ -3394,7 +3394,7 @@ listiter_next(PyObject *self)
     _PyListIterObject *it = (_PyListIterObject *)self;
     Py_ssize_t index = LOAD_SSIZE(it->it_index);
 #ifndef Py_GIL_DISABLED
-    if (seq == NULL) {
+    if (it->it_seq == NULL) {
 #else
     if (index < 0) {
 #endif