Before, units that are used for more than one dependency type get
written multiple times, and so create useless backup files (and
potentially overwrite legit ones).

[root@vagrant ~]# echo '{"database": "example"}' | rolectl deploy databaseserver --settings-stdin 
Deployment can take a long time. To monitor the progress, run 
journalctl -ef -u rolekit
success
[root@vagrant ~]# find /etc/systemd/ -name role-\*
/etc/systemd/system/role-fail-databaseserver-1.service
/etc/systemd/system/postgresql.service.d/role-databaseserver-1.target.conf
/etc/systemd/system/multi-user.target.wants/role-databaseserver-1.target
/etc/systemd/system/syslog.target.d/role-databaseserver-1.target.conf
/etc/systemd/system/role-databaseserver-1.target
/etc/systemd/system/network.target.d/role-databaseserver-1.target.conf
[root@vagrant ~]#
--> no *.old files