Fix an incomaptibility with ocaml-4.13 Switch from m4 to sed OBS-URL: https://build.opensuse.org/package/show/devel:languages:ocaml/ocaml-findlib?expand=0&rev=93
OBS-URL: https://build.opensuse.org/package/show/devel:languages:ocaml/ocaml-findlib?expand=0&rev=78