fix some things

nksrv/LobbyServer/Msgs/User/SetWallpaper.cs

@@ -0,0 +1,22 @@
+using nksrv.Utils;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace nksrv.LobbyServer.Msgs.User
+{
+    [PacketPath("/User/SetWallpaper")]
+    public class SetWallpaper : LobbyMsgHandler
+    {
+        protected override async Task HandleAsync()
+        {
+            var req = await ReadData<ReqSetWallpaper>();
+            var response = new ResSetWallpaper();
+            // todo
+
+            WriteData(response);
+        }
+    }
+}