Merged revision(s) 1623225 from lucene/dev/trunk:
SOLR-6488: Upgrade Solr Cell to TIKA 1.6

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1623227 13f79535-47bb-0310-9956-ffa450edef68