SOLR-6241: disable this test on Jenkins until we can track down the cause of the No registered leader was found after waiting for 60000ms , collection: c8n_1x3_lf slice: shard1 problem

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1611923 13f79535-47bb-0310-9956-ffa450edef68