no need to expose keys which are stored in archiva configuration

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1445899 13f79535-47bb-0310-9956-ffa450edef68
optimize a bit: no need to fully rebuild the bean if no change

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1445900 13f79535-47bb-0310-9956-ffa450edef68