revert most NGINX docker changes

template/docker-compose.nginx.yml

@@ -24,8 +24,6 @@ services:
         depends_on:
             - postgres
         container_name: piped-backend
-        environment:
-          - PORT=PORT_VALUE
     nginx:
         image: nginx:mainline-alpine
         restart: unless-stopped
@@ -48,9 +46,6 @@ services:
             - "traefik.http.routers.piped.rule=Host(`FRONTEND_HOSTNAME`, `BACKEND_HOSTNAME`, `PROXY_HOSTNAME`)"
             - "traefik.http.routers.piped.entrypoints=websecure"
             - "traefik.http.services.piped.loadbalancer.server.port=PORT_VALUE"
-        environment:
-          - PORT=PORT_VALUE
-
     postgres:
         image: postgres:15
         restart: unless-stopped