Update Readme (#660)

Co-authored-by: Lianmin Zheng <lianminzheng@gmail.com>

python/sglang/lang/tracer.py

@@ -3,8 +3,8 @@
 import uuid
 from typing import Any, Callable, Dict, List, Optional, Union
 
-from sglang.backend.base_backend import BaseBackend
 from sglang.global_config import global_config
+from sglang.lang.backend.base_backend import BaseBackend
 from sglang.lang.interpreter import ProgramState, ProgramStateGroup
 from sglang.lang.ir import (
     SglArgument,