Remove 'bufsize' variables from lcb_settings

These are not used

Change-Id: I7068bce872a82237ea447eb43d52ba4e43cfe437
Reviewed-on: http://review.couchbase.org/36544
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>