By using the now working btlr direction of the underlying fly frame,
instead of the character-level workaround.

Change-Id: I3024e3348a30c72f461032b03b88c210f25eb75a
Reviewed-on: https://gerrit.libreoffice.org/73628
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>