Clean up

docker/docker-compose.yml

@@ -63,10 +63,6 @@ services:
     command:
       - /bin/sh
       - -c
-      # - Double dollars, so that the variable is not expanded by Docker Compose
-      # - Surround by quotes, so that the shell does not split the password
-      # - The ${variable:?message} syntax causes shell to exit with a non-zero
-      #   code and print a message, when the variable is not set or empty
       - redis-server --requirepass "$${REDIS_PASSWORD:?REDIS_PASSWORD variable is not set}"
     healthcheck:
       test: