09-troubleshooting.md: minor fix for getting logs from MON

You can check the logs of any container with the following commands:

```bash

docker logs $(docker ps -aqf "name=osm_mon" -n 1)

docker logs $(docker ps -aqf "name=osm_mon.1" -n 1)

docker logs $(docker ps -aqf "name=osm_pol" -n 1)

docker logs $(docker ps -aqf "name=osm_lcm" -n 1)

docker logs $(docker ps -aqf "name=osm_nbi" -n 1)

And the DOCKER_ID can be obtained this way, e.g. for MON

```bash

docker ps -aqf "name=osm_mon" -n 1 --no-trunc

docker ps -aqf "name=osm_mon.1" -n 1 --no-trunc

```

### Changing the log level