update rpcclient for the method estimatefee

[jiangjinyuan]

Please update the method estimatefee in rpcclient! Actually, the Bitcoin ABC has removed nblocks parameter in estimatefee.
You can check this:
https://github.com/Bitcoin-ABC/bitcoin-abc/blob/dba3e93c015250c3a9739e4cce72a5aa260870ff/doc/release-notes/release-notes-0.19.1.md#bitcoin-abc-0191-release-notes

[zquestz]

I can look into this. =)

[mcroni]

any progress with this?

[zquestz]

Confirmed, and thanks for the pointer to the ABC release notes. BCHN inherited that change: estimatefee in src/rpc/mining.cpp takes zero arguments and returns the fee per kilobyte.

The more consequential half turned out to be server side rather than in rpcclient. bchd declared nblocks as a required positional parameter, so a caller written against BCHN that invokes estimatefee with no arguments failed with a params error before the handler ever ran. bchd was the odd one out for anything talking to it.

That is fixed. The parameter is now optional, and omitting it estimates the fee for the next block, which is the closest match to BCHN's behaviour. Passing a value still works, so existing bchd callers are unaffected.

The rpcclient signature you originally asked about, EstimateFee(numBlocks int64), is a breaking change to a published package, so that one is queued for the next major release rather than a patch. estimatepriority sits next to it and ABC removed it outright, so it probably wants the same treatment at the same time.

@mcroni sorry this sat for so long.