Revert "opt: non null (#1091)"

This reverts commit 3c34e43827.

lib/pages/follow/child/child_controller.dart

@@ -48,7 +48,7 @@ class FollowChildController
   @override
   Future<LoadingState<FollowData>> customGetData() {
     if (tagid != null) {
-      return MemberHttp.followUpGroup(mid: mid, tagid: tagid!, pn: page);
+      return MemberHttp.followUpGroup(mid: mid, tagid: tagid, pn: page);
     }
 
     return FollowHttp.followings(

lib/pages/follow/controller.dart

@@ -70,7 +70,7 @@ class FollowController extends GetxController with GetTickerProviderStateMixin {
   }
 
   Future<void> onUpdateTag(MemberTagItemModel item, String tagName) async {
-    final res = await MemberHttp.updateFollowTag(item.tagid!, tagName);
+    final res = await MemberHttp.updateFollowTag(item.tagid, tagName);
     if (res['status']) {
       item.name = tagName;
       tabs.refresh();
@@ -80,7 +80,7 @@ class FollowController extends GetxController with GetTickerProviderStateMixin {
     }
   }
 
-  Future<void> onDelTag(int tagid) async {
+  Future<void> onDelTag(int? tagid) async {
     final res = await MemberHttp.delFollowTag(tagid);
     if (res['status']) {
       followState.value = LoadingState.loading();

lib/pages/follow/view.dart

@@ -202,7 +202,7 @@ class _FollowPageState extends State<FollowPage> {
                     context: context,
                     title: '删除分组',
                     content: '删除后，该分组下的用户依旧保留？',
-                    onConfirm: () => _followController.onDelTag(item.tagid!),
+                    onConfirm: () => _followController.onDelTag(item.tagid),
                   );
                 },
                 dense: true,