[maven-release-plugin] prepare release cellar-2.2.6

git-svn-id: https://svn.apache.org/repos/asf/karaf/cellar/branches/cellar-2.2.x@1484232 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/karaf/cellar/branches/cellar-2.2.x@1484234 13f79535-47bb-0310-9956-ffa450edef68