fix/update-ldap-server-bsi

The upstream Helm chart for the ldap-server has been updated.

It's configuration has changed slightly.

This MR updates the chart reference and adjusts the configuration accordingly.

@OC000024686899 I am closing !76 (closed) as it is a doublette of this one. You do not need to manually create MRs as they are autocreated when pushing a new branch (pointing to the right merge target develop).

FYI: the ldap-notifier gets an error when trying to touch the pvc it shares with the ldap-server. removing the capability drop fixes that. potentially one could add some capability that fixes it but neither do i know what nor do i have the time to try-and-error it out. also ldap-notifier will be dropped sooner rather than later.