use Chaos Monkey's utility method for (re)starting up jetty so that we get it's automatic rety mechanism in the event that the old jetty process hasn't finished releasing the port (merge r1604033)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1604034 13f79535-47bb-0310-9956-ffa450edef68