CBLT-319:  cosmetic improvements to sgw dashboards

Change-Id: If2268c2799a0dcde8a6dbf34be538d38180e1505
Reviewed-on: http://review.couchbase.org/39032
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>