[tests] remove mpi2vch() function
[tests] remove mpi2vch() function

All it does is reverse the bytes order.

pataquets/namecoin-core,jonasschnelli/bitcoin,andreaskern/bitcoin,fujicoin/fujicoin,namecoin/namecore,Xekyo/bitcoin,bitcoin/bitcoin,domob1812/bitcoin,dscotese/bitcoin,AkioNak/bitcoin,AkioNak/bitcoin,bitcoin/bitcoin,domob1812/bitcoin,particl/particl-core,jlopp/statoshi,cdecker/bitcoin,rnicoll/bitcoin,monacoinproject/monacoin,tecnovert/particl-core,ahmedbodi/vertcoin,Xekyo/bitcoin,qtumproject/qtum,sipsorcery/bitcoin,MarcoFalke/bitcoin,ElementsProject/elements,andreaskern/bitcoin,rnicoll/dogecoin,jnewbery/bitcoin,andreaskern/bitcoin,bitcoinknots/bitcoin,kallewoof/bitcoin,fujicoin/fujicoin,mruddy/bitcoin,pstratem/bitcoin,n1bor/bitcoin,namecoin/namecore,fujicoin/fujicoin,tecnovert/particl-core,namecoin/namecoin-core,lateminer/bitcoin,ajtowns/bitcoin,EthanHeilman/bitcoin,cdecker/bitcoin,jamesob/bitcoin,qtumproject/qtum,rnicoll/bitcoin,JeremyRubin/bitcoin,MeshCollider/bitcoin,JeremyRubin/bitcoin,prusnak/bitcoin,n1bor/bitcoin,pstratem/bitcoin,bitcoinknots/bitcoin,mm-s/bitcoin,practicalswift/bitcoin,instagibbs/bitcoin,MeshCollider/bitcoin,alecalve/bitcoin,jonasschnelli/bitcoin,lateminer/bitcoin,practicalswift/bitcoin,pstratem/bitcoin,apoelstra/bitcoin,GroestlCoin/GroestlCoin,yenliangl/bitcoin,jambolo/bitcoin,mruddy/bitcoin,anditto/bitcoin,MarcoFalke/bitcoin,ElementsProject/elements,GroestlCoin/GroestlCoin,Xekyo/bitcoin,achow101/bitcoin,EthanHeilman/bitcoin,jnewbery/bitcoin,lateminer/bitcoin,GroestlCoin/bitcoin,jnewbery/bitcoin,jamesob/bitcoin,vertcoin/vertcoin,midnightmagic/bitcoin,rnicoll/dogecoin,rnicoll/bitcoin,DigitalPandacoin/pandacoin,vertcoin/vertcoin,namecoin/namecore,bitcoinsSG/bitcoin,particl/particl-core,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,n1bor/bitcoin,sipsorcery/bitcoin,midnightmagic/bitcoin,namecoin/namecoin-core,Xekyo/bitcoin,andreaskern/bitcoin,sstone/bitcoin,mruddy/bitcoin,GroestlCoin/GroestlCoin,JeremyRubin/bitcoin,jonasschnelli/bitcoin,bitcoin/bitcoin,DigitalPandacoin/pandacoin,midnightmagic/bitcoin,alecalve/bitcoin,n1bor/bitcoin,midnightmagic/bitcoin,n1bor/bitcoin,qtumproject/qtum,achow101/bitcoin,tecnovert/particl-core,anditto/bitcoin,peercoin/peercoin,DigitalPandacoin/pandacoin,bitcoinsSG/bitcoin,domob1812/bitcoin,MarcoFalke/bitcoin,practicalswift/bitcoin,fanquake/bitcoin,Xekyo/bitcoin,alecalve/bitcoin,bitcoinknots/bitcoin,monacoinproject/monacoin,sstone/bitcoin,rnicoll/bitcoin,mm-s/bitcoin,lateminer/bitcoin,ajtowns/bitcoin,sstone/bitcoin,fujicoin/fujicoin,fanquake/bitcoin,bitcoinsSG/bitcoin,yenliangl/bitcoin,MeshCollider/bitcoin,cdecker/bitcoin,AkioNak/bitcoin,JeremyRubin/bitcoin,Sjors/bitcoin,alecalve/bitcoin,particl/particl-core,rnicoll/dogecoin,pataquets/namecoin-core,GroestlCoin/bitcoin,cdecker/bitcoin,Sjors/bitcoin,tecnovert/particl-core,pstratem/bitcoin,domob1812/namecore,achow101/bitcoin,anditto/bitcoin,sstone/bitcoin,apoelstra/bitcoin,namecoin/namecore,achow101/bitcoin,jambolo/bitcoin,instagibbs/bitcoin,anditto/bitcoin,GroestlCoin/bitcoin,fanquake/bitcoin,namecoin/namecore,particl/particl-core,sipsorcery/bitcoin,domob1812/namecore,ajtowns/bitcoin,yenliangl/bitcoin,jamesob/bitcoin,instagibbs/bitcoin,lateminer/bitcoin,fanquake/bitcoin,AkioNak/bitcoin,litecoin-project/litecoin,bitcoinknots/bitcoin,jlopp/statoshi,sipsorcery/bitcoin,kallewoof/bitcoin,fujicoin/fujicoin,bitcoinsSG/bitcoin,kallewoof/bitcoin,rnicoll/dogecoin,prusnak/bitcoin,yenliangl/bitcoin,jambolo/bitcoin,MarcoFalke/bitcoin,sipsorcery/bitcoin,MarcoFalke/bitcoin,jlopp/statoshi,dscotese/bitcoin,qtumproject/qtum,mruddy/bitcoin,kallewoof/bitcoin,Xekyo/bitcoin,vertcoin/vertcoin,mm-s/bitcoin,rnicoll/bitcoin,domob1812/bitcoin,domob1812/namecore,ahmedbodi/vertcoin,GroestlCoin/bitcoin,vertcoin/vertcoin,tecnovert/particl-core,achow101/bitcoin,andreaskern/bitcoin,fujicoin/fujicoin,ElementsProject/elements,domob1812/bitcoin,jambolo/bitcoin,peercoin/peercoin,practicalswift/bitcoin,EthanHeilman/bitcoin,particl/particl-core,kallewoof/bitcoin,bitcoinsSG/bitcoin,namecoin/namecoin-core,mm-s/bitcoin,prusnak/bitcoin,namecoin/namecoin-core,qtumproject/qtum,domob1812/namecore,JeremyRubin/bitcoin,alecalve/bitcoin,practicalswift/bitcoin,monacoinproject/monacoin,anditto/bitcoin,alecalve/bitcoin,jamesob/bitcoin,sstone/bitcoin,MeshCollider/bitcoin,jlopp/statoshi,jamesob/bitcoin,mm-s/bitcoin,ahmedbodi/vertcoin,jlopp/statoshi,jnewbery/bitcoin,qtumproject/qtum,ahmedbodi/vertcoin,n1bor/bitcoin,domob1812/bitcoin,sipsorcery/bitcoin,ElementsProject/elements,practicalswift/bitcoin,sstone/bitcoin,tecnovert/particl-core,jambolo/bitcoin,rnicoll/dogecoin,apoelstra/bitcoin,ajtowns/bitcoin,rnicoll/bitcoin,ajtowns/bitcoin,ElementsProject/elements,fanquake/bitcoin,peercoin/peercoin,pataquets/namecoin-core,bitcoin/bitcoin,jamesob/bitcoin,dscotese/bitcoin,JeremyRubin/bitcoin,instagibbs/bitcoin,prusnak/bitcoin,mruddy/bitcoin,MeshCollider/bitcoin,andreaskern/bitcoin,fanquake/bitcoin,kallewoof/bitcoin,GroestlCoin/GroestlCoin,namecoin/namecoin-core,jlopp/statoshi,GroestlCoin/bitcoin,instagibbs/bitcoin,litecoin-project/litecoin,Sjors/bitcoin,apoelstra/bitcoin,bitcoinsSG/bitcoin,anditto/bitcoin,cdecker/bitcoin,pataquets/namecoin-core,monacoinproject/monacoin,domob1812/namecore,EthanHeilman/bitcoin,peercoin/peercoin,jambolo/bitcoin,pstratem/bitcoin,vertcoin/vertcoin,qtumproject/qtum,litecoin-project/litecoin,Sjors/bitcoin,GroestlCoin/GroestlCoin,dscotese/bitcoin,vertcoin/vertcoin,achow101/bitcoin,jonasschnelli/bitcoin,pataquets/namecoin-core,bitcoinknots/bitcoin,pataquets/namecoin-core,ElementsProject/elements,GroestlCoin/bitcoin,peercoin/peercoin,instagibbs/bitcoin,particl/particl-core,namecoin/namecoin-core,litecoin-project/litecoin,yenliangl/bitcoin,prusnak/bitcoin,prusnak/bitcoin,yenliangl/bitcoin,ajtowns/bitcoin,MeshCollider/bitcoin,DigitalPandacoin/pandacoin,peercoin/peercoin,jnewbery/bitcoin,litecoin-project/litecoin,GroestlCoin/GroestlCoin,litecoin-project/litecoin,AkioNak/bitcoin,dscotese/bitcoin,EthanHeilman/bitcoin,midnightmagic/bitcoin,Sjors/bitcoin,EthanHeilman/bitcoin,mm-s/bitcoin,apoelstra/bitcoin,ahmedbodi/vertcoin,mruddy/bitcoin,bitcoin/bitcoin,MarcoFalke/bitcoin,namecoin/namecore,jonasschnelli/bitcoin,apoelstra/bitcoin,bitcoin/bitcoin,midnightmagic/bitcoin,lateminer/bitcoin,cdecker/bitcoin,dscotese/bitcoin,monacoinproject/monacoin,monacoinproject/monacoin,domob1812/namecore,ahmedbodi/vertcoin,pstratem/bitcoin,AkioNak/bitcoin