tweak ci-build script to prevent bootstrapped files from causing trouble on "git pull"
tweak ci-build script to prevent bootstrapped files from causing trouble on "git pull"

msprotz/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,eliberis/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,yunxing/ocaml,msprotz/ocaml,yunxing/ocaml,msprotz/ocaml,eliberis/ocaml