Remove code! We don't need to update the waiter

The waiter will be updated by new callers of `change_and_push`.

src/git_kv.ml

@@ -723,8 +723,5 @@ module Make (Pclock : Mirage_clock.PCLOCK) = struct
         (fun err -> `Msg (Fmt.str "error pushing %a" Store.pp_error err))
       >>= fun res ->
       Lwt.wakeup_later wk () ;
-      (match t.change_and_push_waiter with
-       | Some th' -> if th' == th then t.change_and_push_waiter <- None
-       | None -> ());
       Lwt.return res
 end