ui: improve error

ui/lib/settings/general.dart

@@ -170,7 +170,7 @@ class _GeneralState extends ConsumerState<GeneralSettings> {
             ),
           );
         },
-        error: (err, trace) => PoError(msg: "网络错误", err: err),
+        error: (err, trace) => PoNetworkError(err: err),
         loading: () => const MyProgressIndicator());
   }
 }