Update Dockerfile

Dockerfile

@@ -11,7 +11,7 @@ USER root
 RUN pip config set global.index-url https://mirrors.cloud.tencent.com/pypi/simple
 
 # 安装项目依赖
-RUN pip install --no-cache-dir -r requirements.txt
+RUN pip install daphne==3.0.2
 
 # 启动 Daphne 服务器
 CMD ["daphne", "-b", "0.0.0.0", "-p", "8000", "server:application"]