Updated the svn:externals to point on the ldap-client branch

git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/branches/apacheds-subtree-with-dependencies@965548 13f79535-47bb-0310-9956-ffa450edef68
tree: 218bb9f7104435aff736fecf044c91963ddc8e43
  1. NOTICE.txt
  2. README.txt
  3. pom.xml