SOLR-6188: Move CHANGES.txt entry from 6.0.0 to 5.4.0.
SOLR-6188: Move CHANGES.txt entry from 6.0.0 to 5.4.0.


git-svn-id: 308d55f399f3bd9aa0560a10e81a003040006c48@1707771 13f79535-47bb-0310-9956-ffa450edef68

apache/solr,apache/solr,apache/solr,apache/solr,apache/solr