gb_LinkTarget_get_preparation_target is not defined (2nd try)
gb_LinkTarget_get_preparation_target is not defined (2nd try)

gb_ExternalProject_use_unpacked has completely different different
side-effects, so use the manual way/the actually expected part of
the rule

Change-Id: I35edb19c3e768608bbb70314cac7ca908a426c7c
Reviewed-on: https://gerrit.libreoffice.org/1067
Reviewed-by: Michael Stahl <eef8671db506f9731c0438a7613853b6391ca841@redhat.com>
Tested-by: Michael Stahl <eef8671db506f9731c0438a7613853b6391ca841@redhat.com>

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