Fix "archive has no table of contents file" error
Fix "archive has no table of contents file" error

Reported by Kate: https://github.com/ocaml/opam-repository/pull/21765#issuecomment-1185583411

ocaml/opam-repository,ocaml/opam-repository,codinuum/opam-repository,codinuum/opam-repository,pqwy/opam-repository,jhwoodyatt/opam-repository,nberth/opam-repository,Leonidas-from-XIV/opam-repository,pirbo/opam-repository,fpottier/opam-repository,Leonidas-from-XIV/opam-repository,jhwoodyatt/opam-repository,pqwy/opam-repository,kkirstein/opam-repository,nberth/opam-repository,fpottier/opam-repository,pirbo/opam-repository,kkirstein/opam-repository