Fix walk tree test for windows
Fix walk tree test for windows

kurin/restic,fawick/restic,episource/restic,mappu/restic,byo/restic,byo/restic,ckemper67/restic,stuertz/restic,jayme-github/restic,arithmetric/restic,kurin/restic,restic/restic,fawick/restic,middelink/restic,ar-jan/restic,bchapuis/restic,jayme-github/restic,restic/restic,stuertz/restic,howeyc/restic,ar-jan/restic,middelink/restic