message: fix bitpacker bug, reset internal value
diff: @@ -49,6 +49,7 @@ impl BitPacker {
  let bytes = self.mini_buffer.to_le_bytes();
  output.write_all(&bytes[..num_bytes])?;
  self.mini_buffer_written = 0;
  + self.mini_buffer = 0;
  }
  Ok(())
  }
  @@ -61,7 +62,7 @@ impl BitPacker {
  }
  }
  -#[derive(Clone)]
  +#[derive(Clone, Debug, Default)]
  pub struct BitUnpacker {
  num_bits: u64,
  mask: u64,
  