Updates python version to 3.9 and removes now unecessary dependency on sid repo.

Author: AshCorr

Dockerfile

@@ -1,13 +1,12 @@
-FROM tiangolo/uwsgi-nginx:python3.8
+FROM tiangolo/uwsgi-nginx:python3.9
 
 ENV UWSGI_INI /srv/www/yogsite/uwsgi.ini
 
 COPY . /srv/www/yogsite
 COPY nginx.conf /app/nginx.conf
 
-RUN echo "deb http://deb.debian.org/debian sid main" >>  /etc/apt/sources.list
 RUN apt-get update
-RUN apt-get install -y  ffmpeg
+RUN apt-get install -y ffmpeg
 
 RUN pip install -r /srv/www/yogsite/requirements.txt