Comment 3 for bug 1702290

This is essentially a config change breaking the service (re)start. and due to that upgrades.
While the init could be more resilient it is not really a bug but a misconfiguration as identified by Ryan already.

Also the error message (these days) is not misleading at all (tried on cosmic):
  slapd[26348]: sed: can't read /etc/ldap/slapd.d/cn=config.ldif: No such file or directory

Which after deleting the file makes sense :-)