Don't add lcbht.t to htparse test executable

This file is already included via linking couchbaseS. Without this, our
coverage reports are missing lcbht.c since we're not testing the
instrumented object (but rather the one built into the test exe)

Change-Id: I8fa95c04a22e932d49d7f7422012322e12d5e933
Reviewed-on: http://review.couchbase.org/43387
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Subhashni Balakrishnan <b.subhashni@gmail.com>