It did not prevent me from upgrading everything else, but multiarch users should not try to force upgrade of ldap packages right now...
https://buildd.debian.org/status/package.php?p=openldap&suite=unstable (https://buildd.debian.org/status/package.php?p=openldap&suite=unstable)
# apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libldap-2.4-2
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.