message: chore: fix ckb stats example
diff: @@ -85,7 +85,7 @@ pub(crate) fn stats() -> App<'static, 'static> {
  .about(
  "Statics chain infomation\n\
  Example:\n\
  - ckb -- -C <dir> stats -- from 1 --to 500",
  + ckb -C <dir> stats --from 1 --to 500",
  )
  .arg(
  Arg::with_name(ARG_FROM)
  