While `/var/lib/lldap` isn't technically accessible by unprivileged
users thanks to `DynamicUser=true`, a user might prefer and change it to
`DynamicUser=false`.
There is currently also a PR open that intends to make `DynamicUser`
configurable via module option.
As such, `jwt_secret_file`, if bootstrapped by the service start
procedure, might be rendered world-readable due to its permissions
(`0644/-rw-r--r--`) defaulting to the service's umask (`022`) and
`/var/lib/lldap` to `0755/drwxr-xr-x` due to `StateDirectoryMode=0755`.
This would usually be fixed by using `(umask 027; openssl ...)` instead
of just `openssl ...`.
However, it was found that another file (`users.db`), this time
bootstrapped by `lldap` itself, also had insufficient permissions
(`0644/-rw-r--r--`) inherited by the global umask and would be left
world-readable as well.
Due to this, we instead change the service's to `027`.
And to lower the impact for already bootstrapped files on existing
instances like `users.db`, set `StateDirectoryMode=0750`.
