doc: Remove outdated comment
doc: Remove outdated comment

The removed commit is wrong since v0.21.0.

namecoin/namecore,mm-s/bitcoin,sstone/bitcoin,dscotese/bitcoin,AkioNak/bitcoin,GroestlCoin/bitcoin,MeshCollider/bitcoin,achow101/bitcoin,domob1812/namecore,anditto/bitcoin,Xekyo/bitcoin,qtumproject/qtum,instagibbs/bitcoin,qtumproject/qtum,GroestlCoin/GroestlCoin,mruddy/bitcoin,particl/particl-core,fujicoin/fujicoin,sipsorcery/bitcoin,mm-s/bitcoin,MeshCollider/bitcoin,namecoin/namecoin-core,pataquets/namecoin-core,ajtowns/bitcoin,bitcoin/bitcoin,GroestlCoin/bitcoin,MeshCollider/bitcoin,achow101/bitcoin,achow101/bitcoin,andreaskern/bitcoin,AkioNak/bitcoin,rnicoll/bitcoin,prusnak/bitcoin,namecoin/namecoin-core,jambolo/bitcoin,MarcoFalke/bitcoin,ElementsProject/elements,bitcoin/bitcoin,Sjors/bitcoin,yenliangl/bitcoin,JeremyRubin/bitcoin,fujicoin/fujicoin,yenliangl/bitcoin,namecoin/namecore,domob1812/bitcoin,MarcoFalke/bitcoin,GroestlCoin/GroestlCoin,tecnovert/particl-core,qtumproject/qtum,yenliangl/bitcoin,bitcoinknots/bitcoin,jlopp/statoshi,andreaskern/bitcoin,fanquake/bitcoin,tecnovert/particl-core,particl/particl-core,MarcoFalke/bitcoin,namecoin/namecoin-core,JeremyRubin/bitcoin,ajtowns/bitcoin,AkioNak/bitcoin,mruddy/bitcoin,bitcoinsSG/bitcoin,tecnovert/particl-core,kallewoof/bitcoin,fanquake/bitcoin,n1bor/bitcoin,sipsorcery/bitcoin,n1bor/bitcoin,ElementsProject/elements,particl/particl-core,fanquake/bitcoin,mm-s/bitcoin,bitcoin/bitcoin,lateminer/bitcoin,anditto/bitcoin,kallewoof/bitcoin,prusnak/bitcoin,fanquake/bitcoin,jlopp/statoshi,rnicoll/bitcoin,jamesob/bitcoin,bitcoin/bitcoin,anditto/bitcoin,ajtowns/bitcoin,dscotese/bitcoin,tecnovert/particl-core,fanquake/bitcoin,jambolo/bitcoin,jamesob/bitcoin,bitcoinknots/bitcoin,bitcoinsSG/bitcoin,particl/particl-core,sstone/bitcoin,apoelstra/bitcoin,anditto/bitcoin,fujicoin/fujicoin,instagibbs/bitcoin,AkioNak/bitcoin,ajtowns/bitcoin,particl/particl-core,bitcoin/bitcoin,tecnovert/particl-core,jamesob/bitcoin,kallewoof/bitcoin,JeremyRubin/bitcoin,GroestlCoin/bitcoin,yenliangl/bitcoin,qtumproject/qtum,jlopp/statoshi,GroestlCoin/GroestlCoin,qtumproject/qtum,anditto/bitcoin,Sjors/bitcoin,mruddy/bitcoin,sstone/bitcoin,pataquets/namecoin-core,namecoin/namecoin-core,GroestlCoin/bitcoin,Xekyo/bitcoin,GroestlCoin/bitcoin,domob1812/bitcoin,jamesob/bitcoin,prusnak/bitcoin,namecoin/namecore,domob1812/namecore,bitcoinknots/bitcoin,JeremyRubin/bitcoin,dscotese/bitcoin,pataquets/namecoin-core,qtumproject/qtum,apoelstra/bitcoin,bitcoinsSG/bitcoin,namecoin/namecore,jlopp/statoshi,AkioNak/bitcoin,apoelstra/bitcoin,namecoin/namecoin-core,domob1812/namecore,domob1812/namecore,yenliangl/bitcoin,n1bor/bitcoin,domob1812/namecore,jambolo/bitcoin,kallewoof/bitcoin,Xekyo/bitcoin,domob1812/bitcoin,GroestlCoin/bitcoin,sstone/bitcoin,andreaskern/bitcoin,rnicoll/bitcoin,sipsorcery/bitcoin,jlopp/statoshi,lateminer/bitcoin,achow101/bitcoin,andreaskern/bitcoin,pataquets/namecoin-core,fanquake/bitcoin,rnicoll/bitcoin,Sjors/bitcoin,bitcoinsSG/bitcoin,mm-s/bitcoin,sstone/bitcoin,jamesob/bitcoin,bitcoinknots/bitcoin,fujicoin/fujicoin,Xekyo/bitcoin,sipsorcery/bitcoin,prusnak/bitcoin,instagibbs/bitcoin,ElementsProject/elements,pataquets/namecoin-core,lateminer/bitcoin,namecoin/namecore,jamesob/bitcoin,instagibbs/bitcoin,kallewoof/bitcoin,MeshCollider/bitcoin,domob1812/bitcoin,lateminer/bitcoin,pataquets/namecoin-core,apoelstra/bitcoin,GroestlCoin/GroestlCoin,Sjors/bitcoin,particl/particl-core,jambolo/bitcoin,jlopp/statoshi,andreaskern/bitcoin,Xekyo/bitcoin,fujicoin/fujicoin,jambolo/bitcoin,instagibbs/bitcoin,mruddy/bitcoin,ElementsProject/elements,anditto/bitcoin,mm-s/bitcoin,domob1812/bitcoin,MarcoFalke/bitcoin,sipsorcery/bitcoin,dscotese/bitcoin,namecoin/namecoin-core,GroestlCoin/GroestlCoin,rnicoll/bitcoin,bitcoinsSG/bitcoin,apoelstra/bitcoin,yenliangl/bitcoin,tecnovert/particl-core,ElementsProject/elements,MeshCollider/bitcoin,rnicoll/bitcoin,sipsorcery/bitcoin,GroestlCoin/GroestlCoin,ajtowns/bitcoin,namecoin/namecore,fujicoin/fujicoin,dscotese/bitcoin,mm-s/bitcoin,n1bor/bitcoin,instagibbs/bitcoin,achow101/bitcoin,jambolo/bitcoin,bitcoinknots/bitcoin,MeshCollider/bitcoin,ElementsProject/elements,mruddy/bitcoin,prusnak/bitcoin,JeremyRubin/bitcoin,andreaskern/bitcoin,bitcoinsSG/bitcoin,sstone/bitcoin,prusnak/bitcoin,lateminer/bitcoin,achow101/bitcoin,lateminer/bitcoin,JeremyRubin/bitcoin,AkioNak/bitcoin,bitcoin/bitcoin,apoelstra/bitcoin,domob1812/bitcoin,n1bor/bitcoin,mruddy/bitcoin,domob1812/namecore,MarcoFalke/bitcoin,ajtowns/bitcoin,n1bor/bitcoin,MarcoFalke/bitcoin,kallewoof/bitcoin,Xekyo/bitcoin,qtumproject/qtum,dscotese/bitcoin,Sjors/bitcoin