Sequences in reverse order

In the Corgi testnet, there are invalid transactions found on the block [29978](http://corgi.codechain.io/explorer/block/29978) and 29979

In block 29978, there are 2 transactions which were signed by the same signer.

The sequence of the first tx(0x615f65...) is 42929 and it failed.
The sequence of the second tx is 42928.

In addition, the first tx(0x615f65..) appears again in the next block, which is 29979. (But, you wouldn't find it in the explorer because the indexer can't index it.)

首先使用連結的瀏覽器和交易前綴 0x615f65，重現 Corgi testnet 區塊 29978 和 29979 中的交易順序。追蹤序列驗證如何處理這兩筆交易，以及重複交易如何到達索引器；當無效順序和重複出現不再發生，且受影響的交易可以被索引時，即表示完成。

由索引模型根據 Issue 內容生成。