Revert "opt: non null (#1091)"

This reverts commit 3c34e43827.

lib/pages/msg_feed_top/at_me/controller.dart

@@ -36,7 +36,7 @@ class AtMeController extends CommonListController<MsgAtData, MsgAtItem> {
   Future<LoadingState<MsgAtData>> customGetData() =>
       MsgHttp.msgFeedAtMe(cursor: cursor, cursorTime: cursorTime);
 
-  Future<void> onRemove(Object id, int index) async {
+  Future<void> onRemove(dynamic id, int index) async {
     try {
       var res = await MsgHttp.delMsgfeed(2, id);
       if (res['status']) {

lib/pages/msg_feed_top/at_me/view.dart

@@ -104,8 +104,7 @@ class _AtMePageState extends State<AtMePage> {
                     onLongPress: () => showConfirmDialog(
                       context: context,
                       title: '确定删除该通知?',
-                      onConfirm: () =>
-                          _atMeController.onRemove(item.id!, index),
+                      onConfirm: () => _atMeController.onRemove(item.id, index),
                     ),
                     leading: GestureDetector(
                       onTap: () => Get.toNamed('/member?mid=${item.user?.mid}'),