Resolves: fdo#83068 ignore spaces in font-size unit detection

Change-Id: Id9a5c2ee576bd533d8b0a2b4356e319354abbbac
(cherry picked from commit d54b2bd8dcc393bb168386a5c0ec4ce40bb3c6d4)
Reviewed-on: https://gerrit.libreoffice.org/11186
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>