fix tgi details interface (#727)

Co-authored-by: shihaobai <baishihao@sensetime.com>

Author: shihaobai

lightllm/server/api_tgi.py

@@ -130,7 +130,7 @@ async def tgi_generate_impl(request: Request, httpserver_manager: HttpServerMana
             ret["prompt_logprobs"] = prompt_logprobs
     assert ret is not None
     if return_details:
-        ret["beam_sequences"] = beam_sequences
+        ret["details"]["beam_sequences"] = beam_sequences
     # wrap generation inside a Vec to match api-inference
     json_compatible_item_data = jsonable_encoder([ret])
     return JSONResponse(content=json_compatible_item_data)