message: fix: miner cellbase input.
  The cellbase input must contains block number it belongs to, not the block
  number of the previous block.
diff: @@ -117,7 +117,7 @@ impl<C: ChainProvider + 'static> Miner<C> {
  transactions: &[Transaction],
  ) -> Result<Transaction, Error> {
  // NOTE: To generate different cellbase txid, we put header number in the input script
  - let inputs = vec![CellInput::new_cellbase_input(head.raw.number)];
  + let inputs = vec![CellInput::new_cellbase_input(head.raw.number + 1)];
  // NOTE: We could've just used byteorder to serialize u64 and hex string into bytes,
  // but the truth is we will modify this after we designed lock script anyway, so let's
  // stick to the simpler way and just convert everything to a single string, then to UTF8
  