Don't add the authenticator if it's disabled, otherwise we get a NPE later.

git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1446107 13f79535-47bb-0310-9956-ffa450edef68
Declared a variable directoryService to avoid many indirections

git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1446117 13f79535-47bb-0310-9956-ffa450edef68