MB-12364: log disabling and resetting of auto-failover to ns_log

So that those actions are more visible as the should

Change-Id: Ibbeba45a43d92f9585e66d9ee3e7af1a4f6e2d3d
Reviewed-on: http://review.couchbase.org/42215
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>