Use internal libxml for Mac release builds.
Use internal libxml for Mac release builds.

Following up from 49843f0f9788e01805d8d0d27428fe5e6a4cc530, actually
use internal libxml for release builds.

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core