Enable code inside #ifdefs

The cmake script did not check for all variables we had in the
configure script

Change-Id: Ib2146b6fc250fa32e612b482c0ca82611ea2dca9
Reviewed-on: http://review.couchbase.org/32676
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>