Import ErrorPopupMsg in RefineMsgHandler

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/net/client/handlers/RefineMsgHandler.java

@@ -13,6 +13,7 @@ import engine.mbEnums;
 import engine.net.Dispatch;
 import engine.net.client.ClientConnection;
 import engine.net.client.msg.ClientNetMsg;
+import engine.net.client.msg.ErrorPopupMsg;
 import engine.net.client.msg.RefineMsg;
 import engine.net.client.msg.RefinerScreenMsg;
 import engine.objects.*;