Alpha: remove dead alphanet specific code

src/proto_alpha/lib_protocol/src/roll_repr.ml

@@ -36,9 +36,3 @@ module Index = struct
       end
     | _ -> None
 end
-
-let rec too_many_roll next =
-  if Compare.Int32.(next < 100_000l) then
-    0
-  else
-    1 + too_many_roll (Int32.div next 2l)

src/proto_alpha/lib_protocol/src/roll_repr.mli

@@ -28,6 +28,3 @@ module Index : sig
   val to_path: t -> string list -> string list
   val of_path: string list -> t option
 end
-
-(** Hack for the alphanet. *)
-val too_many_roll: t -> int