fix bug 907


git-svn-id: https://foundry.supelec.fr/svn/luatex/trunk@5023 0b2b3880-5936-4365-a048-eb17d2e5a6bf
small patch from Akira/PEB in the filename prompt


git-svn-id: https://foundry.supelec.fr/svn/luatex/trunk@5024 0b2b3880-5936-4365-a048-eb17d2e5a6bf