While the text boundary on a wrap-through frame
will not need text boundary markers for the external text,
it does have relevance for the internal text.
Change-Id: Ica91dc42333a69cfecd10a72a1188d77d1dd4ed7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165395
Tested-by: Jenkins
Reviewed-by: Justin Luth <jluth@mail.com>