"tdf#108608 more Draw text editing responsiveness fixes"

lru_map is fine on Windows, was a bug in the new clear method I
added.

Change-Id: I27565675dfe0f57e2ba3c3e0c50297770761dc6a
Reviewed-on: https://gerrit.libreoffice.org/52728Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>