CBZ archives containing files with non-ascii filenames are not well handled

[greentore]

Icaros sometimes fails to pick the first image in the archive if the filenames contain non-ascii characters.

Example:

00_あ.png
01_あ.png
02_あ_.png

If you zip first 2 images then archive will have no thumbnail. If you zip all 3 then the last one will become the thumbnail.