remove url_decode - unused function
remove url_decode - unused function

marklrh/ocaml-cohttp,mor1/ocaml-cohttp,inhabitedtype/ocaml-cohttp,marklrh/ocaml-cohttp,marklrh/ocaml-cohttp,inhabitedtype/ocaml-cohttp,edwintorok/ocaml-cohttp,mor1/ocaml-cohttp,mor1/ocaml-cohttp,inhabitedtype/ocaml-cohttp,edwintorok/ocaml-cohttp,edwintorok/ocaml-cohttp