CBLT-198:  fix up dpkg --install command again

Change-Id: Icc5fc09cfa3c65346aa2e096f5eaeb7aac3ebf87
Reviewed-on: http://review.couchbase.org/34162
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>