added more diagnostics to upr-replicator startup

Change-Id: Icf186b7fd28737634a69935341007409c0637ee9
Reviewed-on: http://review.couchbase.org/35706
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>