There were a couple of wrong things going on in the `Responder`:
- `check_confirmations` included in 8a10979db0 was not doing a good job keeping track of the missed confirmations, probably due to a overlooked refactor.
- There was an edge case when adding txs to `unconfirmed_txs` on `create_job` that may lead to a transaction being confirmed and unconfirmed at the same time from the `Responder's` pow. It could be triggered by adding two jobs with the same justice_txid.