Update Dockerfile

Dockerfile

@@ -19,5 +19,5 @@ RUN pip3 install virtualenv \
 RUN cd /home/SEEC-Judge \
     && python3 setup.py install
 WORKDIR /home/SEEC-Judge/web
-CMD ["gunicorn","-w", "1", "-b", "0.0.0.0:5000", "app:app","--capture-output","--access-logfile","acc.log","--error-logfile","err.log","--log-level","debug"]
+CMD ["gunicorn","-w", "1", "-b", "0.0.0.0:5000", "app:app","--capture-output","--access-logfile","acc.log","--error-logfile","err.log"]