killed unused stuff in capi_frontend

Change-Id: I3ede3c9108e6638be35ca1dda2cc68b90bc65138
Reviewed-on: http://review.couchbase.org/33177
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>