Another fix for DIRSERVER-1802 : we were creating an array which is too big when we remove a disabled Authenticator, so we end with a null value in the array, which produces a NPE

git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1446146 13f79535-47bb-0310-9956-ffa450edef68