add WithoutOnlineMode setting to login server and update usage in packet inspector

cmd/strom/packet_inspector/main.go

@@ -102,7 +102,7 @@ func Run(args []string) (err error) {
 				return
 			}
 		}
-		_, err = server.ServeLogin(serveeConn, server.WithOtherAccount(acc), server.WithStatus(StatusResponse))
+		_, err = server.ServeLogin(serveeConn, server.WithOtherAccount(acc), server.WithStatus(StatusResponse), server.WithoutOnlineMode())
 		if err != nil {
 			return
 		}

server/login_server.go

@@ -235,6 +235,12 @@ func WithCompatibleVersions(versions ...int32) LoginServerSetting {
 	}
 }
 
+func WithoutOnlineMode() LoginServerSetting {
+	return func(s *LoginServer) {
+		s.OnlineMode = false
+	}
+}
+
 func ServeLogin(c *proto.Conn, settings ...LoginServerSetting) (ret *LoginServer, err error) {
 	ret = &LoginServer{Conn: c}
 	ret.OnlineMode = true