Revert "Soft-delete all per-node keys from config when shunning a node."

This reverts commit f0ae51abca7710e732d6049c379bf766008671a5.

Change-Id: I3d206bc308ee10b8a2f1e8e585cdc9a7f0922c90
Reviewed-on: http://review.couchbase.org/35733
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>