This PR does two small things:
1. The log level, in case it is unset, will now be "calculated" from
`/etc/dms-settings` and not always default to `info`. This way, we
can ensure that more often than not, the log level the user chose
when starting DMS is used everywhere.
2. I noticed that the way I obtained the log level could be used to
obtain any env variable's log level. I therefore added a function to
`utils.sh` in case we use it in the future.
