SOLR-6405: Remove unnecessary attemptCount > 0 check.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1619879 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6405: Update comment around retry pause padding.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1619892 13f79535-47bb-0310-9956-ffa450edef68