remove unnecessary includes

Change-Id: I2876889f6b59aaa4a644a48f6d79656cdfb85c9a
Reviewed-on: http://review.couchbase.org/44115
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>