Hi, Cedric.
If you're talking about `/etc/gluu/conf/ox-ldap.properties` then no, you must not delete it - it's a vital piece of configuration and you'll break your instance. You are right, most of the sensitive credentials data located in `setup.properties.last` is still present on disk in different configuration files, either in plain text, or reversibly-encrypted. There is no easy way around it as different components need to have access to it. So the only point in removing that file is to make it harder for a malicious user to retrieve this data.