Fix sequence issues when creating alternate moves

--HG-- branch : 16.0

tests/test_alternate_ledger.py

@@ -62,7 +62,7 @@
         self.assertEqual(self._count_moves(), 1)
 
     def test_copy(self):
-        move2 = self.move.copy()
+        self.move.copy()
         self.assertEqual(self._count_moves(), 2)
 
     def test_delete(self):