Improve blocksdir functional test.
Improve blocksdir functional test.

A new node should not create an unused `blocks` directory in the root of
the data directory when `-testnet` or `-regtest` is specified.

nikkitan/bitcoin,anditto/bitcoin,MeshCollider/bitcoin,gjhiggins/vcoincore,monacoinproject/monacoin,ahmedbodi/vertcoin,jonasschnelli/bitcoin,jnewbery/bitcoin,jnewbery/bitcoin,qtumproject/qtum,r8921039/bitcoin,tjps/bitcoin,droark/bitcoin,FeatherCoin/Feathercoin,sstone/bitcoin,EthanHeilman/bitcoin,r8921039/bitcoin,sstone/bitcoin,n1bor/bitcoin,JeremyRubin/bitcoin,practicalswift/bitcoin,particl/particl-core,bespike/litecoin,pataquets/namecoin-core,EthanHeilman/bitcoin,mruddy/bitcoin,OmniLayer/omnicore,OmniLayer/omnicore,GroestlCoin/bitcoin,mitchellcash/bitcoin,Xekyo/bitcoin,bitcoin/bitcoin,myriadcoin/myriadcoin,jonasschnelli/bitcoin,monacoinproject/monacoin,lateminer/bitcoin,midnightmagic/bitcoin,nikkitan/bitcoin,bespike/litecoin,n1bor/bitcoin,apoelstra/bitcoin,myriadcoin/myriadcoin,ElementsProject/elements,practicalswift/bitcoin,bespike/litecoin,ElementsProject/elements,jnewbery/bitcoin,wellenreiter01/Feathercoin,afk11/bitcoin,particl/particl-core,bitcoinsSG/bitcoin,instagibbs/bitcoin,mitchellcash/bitcoin,myriadcoin/myriadcoin,sipsorcery/bitcoin,apoelstra/bitcoin,afk11/bitcoin,lateminer/bitcoin,ahmedbodi/vertcoin,GroestlCoin/GroestlCoin,jtimon/bitcoin,namecoin/namecore,fanquake/bitcoin,OmniLayer/omnicore,CryptArc/bitcoin,MeshCollider/bitcoin,droark/bitcoin,vertcoin/vertcoin,MeshCollider/bitcoin,litecoin-project/litecoin,nikkitan/bitcoin,mitchellcash/bitcoin,nikkitan/bitcoin,ElementsProject/elements,GroestlCoin/bitcoin,fujicoin/fujicoin,wellenreiter01/Feathercoin,Sjors/bitcoin,Sjors/bitcoin,FeatherCoin/Feathercoin,fanquake/bitcoin,MeshCollider/bitcoin,yenliangl/bitcoin,kallewoof/bitcoin,mruddy/bitcoin,anditto/bitcoin,jonasschnelli/bitcoin,JeremyRubin/bitcoin,domob1812/namecore,vertcoin/vertcoin,mm-s/bitcoin,instagibbs/bitcoin,tjps/bitcoin,droark/bitcoin,jambolo/bitcoin,jamesob/bitcoin,JeremyRubin/bitcoin,cdecker/bitcoin,bitcoinsSG/bitcoin,FeatherCoin/Feathercoin,namecoin/namecoin-core,andreaskern/bitcoin,rnicoll/dogecoin,jambolo/bitcoin,fujicoin/fujicoin,mruddy/bitcoin,kallewoof/bitcoin,bitcoin/bitcoin,tecnovert/particl-core,bitcoinknots/bitcoin,gjhiggins/vcoincore,sipsorcery/bitcoin,jlopp/statoshi,litecoin-project/litecoin,monacoinproject/monacoin,qtumproject/qtum,apoelstra/bitcoin,GroestlCoin/bitcoin,anditto/bitcoin,pataquets/namecoin-core,ahmedbodi/vertcoin,mruddy/bitcoin,EthanHeilman/bitcoin,AkioNak/bitcoin,wellenreiter01/Feathercoin,Sjors/bitcoin,lateminer/bitcoin,myriadcoin/myriadcoin,n1bor/bitcoin,fujicoin/fujicoin,Xekyo/bitcoin,pstratem/bitcoin,litecoin-project/litecoin,peercoin/peercoin,prusnak/bitcoin,FeatherCoin/Feathercoin,bitcoinknots/bitcoin,jtimon/bitcoin,tecnovert/particl-core,namecoin/namecore,midnightmagic/bitcoin,tecnovert/particl-core,bitcoinsSG/bitcoin,peercoin/peercoin,gjhiggins/vcoincore,rnicoll/dogecoin,apoelstra/bitcoin,qtumproject/qtum,jamesob/bitcoin,qtumproject/qtum,jtimon/bitcoin,vertcoin/vertcoin,domob1812/namecore,midnightmagic/bitcoin,jonasschnelli/bitcoin,kallewoof/bitcoin,jtimon/bitcoin,ElementsProject/elements,rnicoll/bitcoin,CryptArc/bitcoin,afk11/bitcoin,instagibbs/bitcoin,droark/bitcoin,r8921039/bitcoin,jamesob/bitcoin,jtimon/bitcoin,pataquets/namecoin-core,myriadteam/myriadcoin,andreaskern/bitcoin,pstratem/bitcoin,jambolo/bitcoin,MarcoFalke/bitcoin,tjps/bitcoin,domob1812/bitcoin,MarcoFalke/bitcoin,wellenreiter01/Feathercoin,droark/bitcoin,jambolo/bitcoin,untrustbank/litecoin,achow101/bitcoin,anditto/bitcoin,vertcoin/vertcoin,ajtowns/bitcoin,MarcoFalke/bitcoin,instagibbs/bitcoin,achow101/bitcoin,fanquake/bitcoin,instagibbs/bitcoin,GroestlCoin/GroestlCoin,r8921039/bitcoin,sstone/bitcoin,cdecker/bitcoin,EthanHeilman/bitcoin,instagibbs/bitcoin,DigitalPandacoin/pandacoin,ahmedbodi/vertcoin,lateminer/bitcoin,untrustbank/litecoin,litecoin-project/litecoin,mitchellcash/bitcoin,yenliangl/bitcoin,DigitalPandacoin/pandacoin,practicalswift/bitcoin,Xekyo/bitcoin,afk11/bitcoin,domob1812/bitcoin,prusnak/bitcoin,pataquets/namecoin-core,mm-s/bitcoin,rnicoll/bitcoin,ElementsProject/elements,OmniLayer/omnicore,domob1812/namecore,alecalve/bitcoin,midnightmagic/bitcoin,lateminer/bitcoin,peercoin/peercoin,AkioNak/bitcoin,rnicoll/bitcoin,alecalve/bitcoin,prusnak/bitcoin,MeshCollider/bitcoin,mm-s/bitcoin,GroestlCoin/GroestlCoin,yenliangl/bitcoin,myriadteam/myriadcoin,jamesob/bitcoin,DigitalPandacoin/pandacoin,andreaskern/bitcoin,pstratem/bitcoin,dscotese/bitcoin,jamesob/bitcoin,afk11/bitcoin,sipsorcery/bitcoin,tecnovert/particl-core,GroestlCoin/GroestlCoin,myriadteam/myriadcoin,bitcoin/bitcoin,bitcoinsSG/bitcoin,qtumproject/qtum,mitchellcash/bitcoin,mruddy/bitcoin,cdecker/bitcoin,Xekyo/bitcoin,EthanHeilman/bitcoin,tjps/bitcoin,dscotese/bitcoin,practicalswift/bitcoin,dscotese/bitcoin,particl/particl-core,bespike/litecoin,bitcoin/bitcoin,anditto/bitcoin,r8921039/bitcoin,mm-s/bitcoin,DigitalPandacoin/pandacoin,namecoin/namecoin-core,sipsorcery/bitcoin,jlopp/statoshi,peercoin/peercoin,andreaskern/bitcoin,alecalve/bitcoin,nikkitan/bitcoin,ajtowns/bitcoin,rnicoll/bitcoin,vertcoin/vertcoin,jlopp/statoshi,CryptArc/bitcoin,namecoin/namecoin-core,domob1812/bitcoin,JeremyRubin/bitcoin,peercoin/peercoin,ahmedbodi/vertcoin,bitcoinknots/bitcoin,domob1812/namecore,fujicoin/fujicoin,bespike/litecoin,MarcoFalke/bitcoin,alecalve/bitcoin,jambolo/bitcoin,MeshCollider/bitcoin,particl/particl-core,FeatherCoin/Feathercoin,ElementsProject/elements,AkioNak/bitcoin,gjhiggins/vcoincore,GroestlCoin/bitcoin,midnightmagic/bitcoin,particl/particl-core,wellenreiter01/Feathercoin,apoelstra/bitcoin,namecoin/namecore,untrustbank/litecoin,myriadteam/myriadcoin,GroestlCoin/GroestlCoin,achow101/bitcoin,rnicoll/dogecoin,FeatherCoin/Feathercoin,monacoinproject/monacoin,jtimon/bitcoin,mitchellcash/bitcoin,dscotese/bitcoin,jlopp/statoshi,peercoin/peercoin,namecoin/namecoin-core,JeremyRubin/bitcoin,myriadteam/myriadcoin,domob1812/namecore,tjps/bitcoin,bitcoin/bitcoin,dscotese/bitcoin,rnicoll/dogecoin,sipsorcery/bitcoin,bitcoinknots/bitcoin,alecalve/bitcoin,tecnovert/particl-core,dscotese/bitcoin,monacoinproject/monacoin,ajtowns/bitcoin,fujicoin/fujicoin,Xekyo/bitcoin,sipsorcery/bitcoin,rnicoll/dogecoin,domob1812/bitcoin,untrustbank/litecoin,ajtowns/bitcoin,namecoin/namecore,mm-s/bitcoin,CryptArc/bitcoin,myriadteam/myriadcoin,jnewbery/bitcoin,bitcoinknots/bitcoin,cdecker/bitcoin,practicalswift/bitcoin,rnicoll/bitcoin,untrustbank/litecoin,Xekyo/bitcoin,mruddy/bitcoin,CryptArc/bitcoin,droark/bitcoin,jamesob/bitcoin,EthanHeilman/bitcoin,namecoin/namecore,gjhiggins/vcoincore,Sjors/bitcoin,pataquets/namecoin-core,DigitalPandacoin/pandacoin,afk11/bitcoin,namecoin/namecoin-core,domob1812/bitcoin,jambolo/bitcoin,fanquake/bitcoin,AkioNak/bitcoin,particl/particl-core,n1bor/bitcoin,apoelstra/bitcoin,bitcoin/bitcoin,OmniLayer/omnicore,fujicoin/fujicoin,andreaskern/bitcoin,domob1812/namecore,namecoin/namecoin-core,fanquake/bitcoin,CryptArc/bitcoin,prusnak/bitcoin,pstratem/bitcoin,kallewoof/bitcoin,ajtowns/bitcoin,litecoin-project/litecoin,tjps/bitcoin,vertcoin/vertcoin,rnicoll/bitcoin,pstratem/bitcoin,bespike/litecoin,prusnak/bitcoin,litecoin-project/litecoin,Sjors/bitcoin,pataquets/namecoin-core,yenliangl/bitcoin,fanquake/bitcoin,alecalve/bitcoin,bitcoinsSG/bitcoin,gjhiggins/vcoincore,mm-s/bitcoin,practicalswift/bitcoin,namecoin/namecore,prusnak/bitcoin,sstone/bitcoin,ajtowns/bitcoin,MarcoFalke/bitcoin,midnightmagic/bitcoin,wellenreiter01/Feathercoin,cdecker/bitcoin,kallewoof/bitcoin,myriadcoin/myriadcoin,n1bor/bitcoin,anditto/bitcoin,OmniLayer/omnicore,yenliangl/bitcoin,jnewbery/bitcoin,cdecker/bitcoin,jlopp/statoshi,monacoinproject/monacoin,domob1812/bitcoin,r8921039/bitcoin,n1bor/bitcoin,GroestlCoin/GroestlCoin,qtumproject/qtum,DigitalPandacoin/pandacoin,achow101/bitcoin,myriadcoin/myriadcoin,ahmedbodi/vertcoin,yenliangl/bitcoin,AkioNak/bitcoin,sstone/bitcoin,lateminer/bitcoin,kallewoof/bitcoin,AkioNak/bitcoin,nikkitan/bitcoin,sstone/bitcoin,JeremyRubin/bitcoin,andreaskern/bitcoin,achow101/bitcoin,jonasschnelli/bitcoin,tecnovert/particl-core,untrustbank/litecoin,qtumproject/qtum,bitcoinsSG/bitcoin,MarcoFalke/bitcoin,achow101/bitcoin,pstratem/bitcoin,GroestlCoin/bitcoin,jlopp/statoshi,GroestlCoin/bitcoin