[Bug]: 通义千问请配置 DASHSCOPE_API_KEY

### Installation Method | 安装方法与平台

Anaconda (I used latest requirements.txt)

### Version | 版本

Latest | 最新版

### OS | 操作系统

Windows

### Describe the bug | 简述

我在config_private.py添加了api_key`API_KEY = "sk-fxxxxxxxxxxxxxxxxab"`；模型选择添加了通义千问
```
LLM_MODEL = "qwen-turbo" # 可选 ↓↓↓
AVAIL_LLM_MODELS = ["qwen-turbo", "qwen-plus", "qwen-max", "qwen-local",
"gpt-4-1106-preview", "gpt-4-turbo-preview", "gpt-4-vision-preview",
"gpt-4o", "gpt-4-turbo", "gpt-4-turbo-2024-04-09",
"gpt-3.5-turbo-1106", "gpt-3.5-turbo-16k", "gpt-3.5-turbo", "azure-gpt-3.5",
"gpt-4", "gpt-4-32k", "azure-gpt-4", "glm-4", "glm-4v", "glm-3-turbo",
"gemini-pro", "chatglm3"
]
```
此外，我再电脑环境变量新建了DASHSCOPE_API_KEY
当我开始对话的时候还是说**请配置 DASHSCOPE_API_KEY**

### Screen Shot | 有帮助的截图



### Terminal Traceback & Material to Help Reproduce Bugs | 终端traceback（如有） + 帮助我们复现的测试材料样本（如有）


Start by checking config_private.py and the model-selection settings in the latest requirements.txt setup, then trace how the qwen-turbo conversation reads DASHSCOPE_API_KEY on Windows. Reproduce the reported prompt and confirm that a correctly configured key allows the conversation to start without the configuration error.

Written by the indexing model from the issue text.