container/mts/meta: make Delete method correctly update order field

container/mts/meta/meta.go

@@ -142,7 +142,7 @@ func (m *Data) Delete(key string) {
 		delete(m.data, key)
 		for i, k := range m.order {
 			if k == key {
-				copy(m.order[:i], m.order[i+1:])
+				copy(m.order[i:], m.order[i+1:])
 				m.order = m.order[:len(m.order)-1]
 				break
 			}