increase worker connections (#1179)

## Description:
Once or twice a week nginx crashes with "768 worker_connections are not
enough while connecting to upstream"
So increase number of allowed connections.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

<DISCORD USERNAME>

Dockerfile

@@ -47,6 +47,9 @@ RUN npm run build-prod
 # https://openfront.io/commit.txt
 RUN echo "$GIT_COMMIT" > static/commit.txt
 
+# Update worker_connections in the existing nginx.conf
+RUN sed -i 's/worker_connections [0-9]*/worker_connections 8192/' /etc/nginx/nginx.conf
+
 # Copy Nginx configuration and ensure it's used instead of the default
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 RUN rm -f /etc/nginx/sites-enabled/default