sw HTML import: fix height of images when it is missing and width is relative
This is similar to commit
456abae730a787693c3ad98f7e57eba5f6163a76 (sw
HTML import: fix height of OLE objs when it is missing and width is
relative, 2022-09-06), but this is for images, while that was for OLE
objects.
The idea is still that in case only axis is specified in the HTML and
that's a relative percentage, then the ratio should be taken from the
bitmap and it should be kept.
Change-Id: I36184ff6531bff2775013462cd8cc711e1a249c5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/140178
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins