KARAF-2231 Avoid ConcurrentModificationException by copying the Set

git-svn-id: https://svn.apache.org/repos/asf/karaf/branches/karaf-2.3.x@1454945 13f79535-47bb-0310-9956-ffa450edef68
KARAF-2231 Avoid ConcurrentModificationException by copying the Set

git-svn-id: https://svn.apache.org/repos/asf/karaf/branches/karaf-2.x@1454947 13f79535-47bb-0310-9956-ffa450edef68