test: add coverage for unknown network in -onlynet
test: add coverage for unknown network in -onlynet

GroestlCoin/GroestlCoin,Xekyo/bitcoin,GroestlCoin/bitcoin,bitcoinsSG/bitcoin,fujicoin/fujicoin,mruddy/bitcoin,AkioNak/bitcoin,mruddy/bitcoin,namecoin/namecoin-core,GroestlCoin/GroestlCoin,AkioNak/bitcoin,domob1812/bitcoin,jamesob/bitcoin,fanquake/bitcoin,lateminer/bitcoin,instagibbs/bitcoin,sipsorcery/bitcoin,domob1812/bitcoin,sstone/bitcoin,particl/particl-core,sipsorcery/bitcoin,GroestlCoin/bitcoin,jambolo/bitcoin,lateminer/bitcoin,ajtowns/bitcoin,domob1812/bitcoin,bitcoinsSG/bitcoin,GroestlCoin/bitcoin,fanquake/bitcoin,mruddy/bitcoin,kallewoof/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,namecoin/namecore,bitcoin/bitcoin,namecoin/namecoin-core,mruddy/bitcoin,instagibbs/bitcoin,andreaskern/bitcoin,bitcoinsSG/bitcoin,GroestlCoin/GroestlCoin,ajtowns/bitcoin,namecoin/namecoin-core,mruddy/bitcoin,ajtowns/bitcoin,ajtowns/bitcoin,instagibbs/bitcoin,kallewoof/bitcoin,lateminer/bitcoin,Xekyo/bitcoin,sstone/bitcoin,AkioNak/bitcoin,tecnovert/particl-core,sipsorcery/bitcoin,fujicoin/fujicoin,GroestlCoin/GroestlCoin,instagibbs/bitcoin,bitcoin/bitcoin,jamesob/bitcoin,GroestlCoin/bitcoin,AkioNak/bitcoin,AkioNak/bitcoin,lateminer/bitcoin,particl/particl-core,domob1812/bitcoin,jamesob/bitcoin,fanquake/bitcoin,particl/particl-core,GroestlCoin/GroestlCoin,instagibbs/bitcoin,namecoin/namecore,instagibbs/bitcoin,jamesob/bitcoin,fujicoin/fujicoin,bitcoinsSG/bitcoin,bitcoinsSG/bitcoin,namecoin/namecoin-core,fanquake/bitcoin,kallewoof/bitcoin,ajtowns/bitcoin,jambolo/bitcoin,bitcoin/bitcoin,jambolo/bitcoin,tecnovert/particl-core,mruddy/bitcoin,AkioNak/bitcoin,particl/particl-core,lateminer/bitcoin,kallewoof/bitcoin,tecnovert/particl-core,particl/particl-core,Xekyo/bitcoin,domob1812/bitcoin,fanquake/bitcoin,GroestlCoin/bitcoin,Xekyo/bitcoin,domob1812/bitcoin,tecnovert/particl-core,jamesob/bitcoin,andreaskern/bitcoin,sstone/bitcoin,fujicoin/fujicoin,GroestlCoin/GroestlCoin,tecnovert/particl-core,sstone/bitcoin,ajtowns/bitcoin,namecoin/namecore,namecoin/namecore,sipsorcery/bitcoin,bitcoinsSG/bitcoin,kallewoof/bitcoin,jamesob/bitcoin,namecoin/namecore,bitcoin/bitcoin,andreaskern/bitcoin,particl/particl-core,kallewoof/bitcoin,GroestlCoin/bitcoin,bitcoin/bitcoin,andreaskern/bitcoin,sstone/bitcoin,Xekyo/bitcoin,jambolo/bitcoin,tecnovert/particl-core,andreaskern/bitcoin,Xekyo/bitcoin,namecoin/namecore,fujicoin/fujicoin,andreaskern/bitcoin,jambolo/bitcoin,fujicoin/fujicoin,namecoin/namecoin-core,lateminer/bitcoin,namecoin/namecoin-core,sipsorcery/bitcoin,sstone/bitcoin,fanquake/bitcoin,bitcoin/bitcoin