[BUG] 上传的txt文档，如果扩展名是大写”TXT“，报错

[RayYe586]

上传的txt文档，如果扩展名是大写”TXT“，报错：
Traceback (most recent call last):
File "/home/bso/venv/chatglm2_6b_venv/lib/python3.10/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 552, in _run_script
exec(code, module.dict)
File "/home/bso/src/srcllm/langchain-ChatGLM/webui.py", line 56, in
pages[selected_page]"func"
File "/home/bso/src/srcllm/langchain-ChatGLM/webui_pages/knowledge_base/knowledge_base.py", line 138, in knowledge_base_page
ret = api.upload_kb_doc(f, kb)
File "/home/bso/src/srcllm/langchain-ChatGLM/webui_pages/utils.py", line 491, in upload_kb_doc
return response.json()
File "/home/bso/venv/chatglm2_6b_venv/lib/python3.10/site-packages/httpx/_models.py", line 756, in json
return jsonlib.loads(self.text, **kwargs)
File "/usr/local/lib/python3.10/json/init.py", line 346, in loads
return _default_decoder.decode(s)
File "/usr/local/lib/python3.10/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/local/lib/python3.10/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

[xain]

#1128 我提交了一个pr修正了这个问题。