[maven-release-plugin] prepare release apache-empire-db-2.4.2-rc1

git-svn-id: https://svn.apache.org/repos/asf/empire-db/trunk@1528948 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/empire-db/trunk@1528950 13f79535-47bb-0310-9956-ffa450edef68