Potential issue with PSBT deserialization code

[hax0kartik]

Hello, while reading Drongo's src code I have come across a potential issue.

Drongo's PSBTEntry constructor is incorrectly implemented as it assumes the keyType to be a single byte. However, according to BIP 174, keyType is a compactInt.

Here's the relevant code in btc core.

[craigraw]

Thanks for pointing this out. Fixed in d73d343. Drongo will now successfully parse keyType entries that are larger than a single byte. Since there are no known types that use these large numbers it will simply log a warning, but it is certainly better than failing to parse the PSBT.