guix: Update hint messages to mention guix-clean
guix: Update hint messages to mention guix-clean

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