The source project of this merge request has been removed.
Fix building against OpenLDAP 2.5+
In recent releases of OpenLDAP only provide libldap and not libldap_r.
From https://www.openldap.org/software/roadmap.html:
OpenLDAP 2.5 (released April 2021)
Library enhancements
libldap_r has been merged with libldap