minor improvement

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1636908 13f79535-47bb-0310-9956-ffa450edef68
OAK-2008 : authorization setup for closed user groups (wip)

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1636909 13f79535-47bb-0310-9956-ffa450edef68