ZOOKEEPER-3817: suppress log4j SmtpAppender related CVE-2020-9488
Author: Mate Szalay-Beko <symat@apache.org>
Reviewers: Enrico Olivelli <eolivelli@apache.org>
Closes #1346 from symat/ZOOKEEPER-3817
(cherry picked from commit f6b54a6cd227ac37f28803f45d7287c7fd3a8142)
Signed-off-by: Enrico Olivelli <eolivelli@apache.org>