fix ListMonitor demo for iOS 13

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/ListObserverDemoViewController.swift

@@ -260,9 +260,8 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
     }
     
     func listMonitor(_ monitor: ListMonitor<Palette>, didMoveObject object: Palette, fromIndexPath: IndexPath, toIndexPath: IndexPath) {
-        
-        self.tableView.deleteRows(at: [fromIndexPath], with: .automatic)
-        self.tableView.insertRows(at: [toIndexPath], with: .automatic)
+
+        self.tableView.moveRow(at: fromIndexPath, to: toIndexPath)
     }