Update Dockerfile

reduce copied files

Dockerfile

@@ -1,7 +1,7 @@
 FROM python:3.9-alpine
 LABEL Maintainer="LRVT"
 
-COPY . /app
+COPY requirements.txt xingdumper.py /app/.
 RUN pip3 install -r /app/requirements.txt
 
 WORKDIR /app