Use the added share/debian-edu-config/sudo-ldap.conf file (commit 2b45ad04) to
provide the last bit of information besides those contained in nslcd.conf and
adjust cf3/cf.ldapclient accordingly. [In case /etc/sudo-ldap.conf is missing,
the sudo-ldap package creates a link pointing to the /etc/ldap/ldap.conf file.]

With this change both /etc/nslcd.conf and /etc/ldap/ldap.conf can be left
unmodified.