Log Message:
bitcoin: updated to 0.20.1

0.20.1 change log

Mining
* Fix GBT: Restore "!segwit" and "csv" to "rules" \ 
key (luke-jr)

P2P protocol and network code
* Replace automatic bans with discouragement filter (sipa)

Wallet
* Handle concurrent wallet loading (promag)
* Minimal fix to restore conflicted transaction notifications (ryanofsky)

RPC and other APIs
* Increment input value sum only once per UTXO in decodepsbt (fanquake)
* psbt: Increment input value sum only once per UTXO in decodepsbt (achow101)
* psbt: Include and allow both non_witness_utxo and witness_utxo for segwit \ 
inputs (achow101)

GUI
* Add missing QPainterPath include (achow101)
* update Qt base translations for macOS release (fanquake)

Build system
* improve build OS configure output (skmcontrib)
* qt, build: Fix QFileDialog for static builds (hebasto)

Tests and QA
* Remove cached directories and associated script blocks from appveyor config \ 
(sipsorcery)
* appveyor: Remove clcache (MarcoFalke)

Miscellaneous
* util: Don't reference errno when pthread fails (miztake)
* Fix locking on WSL using flock instead of fcntl