setup/unixstyle-install: fix up only installed ".desktop" files
setup/unixstyle-install: fix up only installed ".desktop" files

Closes PR 14354

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket