Filter out OS not needing -ldl

Change-Id: I5863de6d8b1f0fe2419ea7419b1ff90087bb513d
Reviewed-on: https://gerrit.libreoffice.org/9715
Tested-by: Michael Stahl <mstahl@redhat.com>
Reviewed-by: Michael Stahl <mstahl@redhat.com>