Compatibility with re.1.8.0 and older

The type annotations constrained 're' version which in turn constrained
ocaml's version.

Author: Julow

src/baselib/ocsigen_stream.ml

@@ -189,7 +189,7 @@ let substream delim s =
           then enlarge_stream stre >>= aux
           else
             try
-              let p, (_ : Re.Group.t) =
+              let p, (_ : Re.substrings) =
                 Ocsigen_lib.Netstring_pcre.search_forward rdelim s 0
               in
               cont (String.sub s 0 p) (fun () ->

src/server/ocsigen_local_files.ml

@@ -102,7 +102,7 @@ let check_dotdot =
     try
       ignore
         (Ocsigen_lib.Netstring_pcre.search_forward regexp filename 0
-         : int * Re.Group.t);
+         : int * Re.substrings);
       false
     with Not_found -> true