[maven-release-plugin] copy for tag org.apache.sling.jcr.jackrabbit.usermanager-2.2.6

git-svn-id: https://svn.apache.org/repos/asf/sling/tags/org.apache.sling.jcr.jackrabbit.usermanager-2.2.6@1789643 13f79535-47bb-0310-9956-ffa450edef68