Update Dockerfile

Signed-off-by: techopsmasters <163403479+techopsmasters@users.noreply.github.com>

nginx-wsgi-flask/nginx/Dockerfile

@@ -1,7 +1,7 @@
 FROM nginx:1.19.7-alpine
 
 # Add bash for boot cmd
-RUN apk add bash
+RUN apt add bash
 
 # Add nginx.conf to container
 COPY --chown=nginx:nginx nginx.conf /etc/nginx/nginx.conf