Trusted proxy

## Description 

Add `TRUSTED_PROXIES` variable to nextcloud container.

Need to be share with subnet default network on ipam.

See: https://docs.docker.com/reference/compose-file/networks/#ipam

## Proto

```yaml
networks:
  default:
    ipam:
      driver: bridge
      config:
        - subnet: ${TRUSTED_PROXY:?}
```