remove an unused alloc
remove an unused alloc

akkakks/json_to_model,clowwindy/json_to_model,LiuDeng/json_to_model,LiuDeng/json_to_model,akkakks/json_to_model,clowwindy/json_to_model,LiuDeng/json_to_model,clowwindy/json_to_model,akkakks/json_to_model