NET: Bump protocol version for witness sync (again)
NET: Bump protocol version for witness sync (again)

There are some nodes in the wild using 70019 from a single previous accidental release, so we move on to 70020 instead

nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official