MB-22122 preserve unsent audit events even if ns_audit is restarted
MB-22122 preserve unsent audit events even if ns_audit is restarted

Change-Id: I6aab21f79172ee443bc038cbe0c4a7dddb6e9072
Reviewed-on: http://review.couchbase.org/78376
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server