Vote passed with no changes required, so creating formal release tag

git-svn-id: https://svn.apache.org/repos/asf/jakarta/jmeter/tags/v2_3_1@598986 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: a8784cf44714a47b4c54c3c466e76903aa2502d0