CA-147161: Discard messages after logging to remote host

Make rsyslog discard messages after they have been logged locally and
sent to a remote host to prevent the default rules from picking them up.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Merge pull request #1959 from rosslagerwall/rsyslog-fix

CA-147161: Discard messages after logging to remote host