The currently used version (1.5.5) is seven years old and will not maintained anymore.
http://directory.apache.org/apacheds/download-old-versions.html

We should discuss if it make sense to upgrade to a newer version of the Apache DS (currently 2.0.0-M21), in the consequence we must rewrite the test cases so they uses the newer api.
Another solution suggested by Robert should be discuss, perhaps it make sense to replace the plugin with a user sync task, which syncs the users from ldap in the cockpit like jira did.