Fixes an issue where SSH server is available but users can't login because LDAP
user services are not yet started.
Tests performed:
- Installed new ssh systemd override conf, rebooted, ensured that the sshd
service starts after the nslcd service.
Relates to #2452.
Signed-off-by: Veiko Aasa <veiko17@disroot.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>
