Fix compiler warnings emitted when compiling under stock OpenBSD 6.3
Fix compiler warnings emitted when compiling under stock OpenBSD 6.3

Sjors/bitcoin,dscotese/bitcoin,dscotese/bitcoin,bitcoin/bitcoin,peercoin/peercoin,r8921039/bitcoin,randy-waterhouse/bitcoin,droark/bitcoin,bitcoinknots/bitcoin,lbryio/lbrycrd,jonasschnelli/bitcoin,lateminer/bitcoin,afk11/bitcoin,mitchellcash/bitcoin,jlopp/statoshi,GlobalBoost/GlobalBoost,digibyte/digibyte,GroestlCoin/bitcoin,vertcoin/vertcoin,qtumproject/qtum,BTCGPU/BTCGPU,peercoin/peercoin,ajtowns/bitcoin,thrasher-/litecoin,ahmedbodi/vertcoin,lateminer/bitcoin,ericshawlinux/bitcoin,jambolo/bitcoin,yenliangl/bitcoin,Kogser/bitcoin,guncoin/guncoin,ajtowns/bitcoin,yenliangl/bitcoin,GlobalBoost/GlobalBoost,OmniLayer/omnicore,achow101/bitcoin,alecalve/bitcoin,ElementsProject/elements,kazcw/bitcoin,yenliangl/bitcoin,mitchellcash/bitcoin,midnightmagic/bitcoin,MeshCollider/bitcoin,MarcoFalke/bitcoin,lateminer/bitcoin,tecnovert/particl-core,joshrabinowitz/bitcoin,sstone/bitcoin,lateminer/bitcoin,jambolo/bitcoin,mruddy/bitcoin,vmp32k/litecoin,anditto/bitcoin,domob1812/bitcoin,mruddy/bitcoin,jamesob/bitcoin,jtimon/bitcoin,JeremyRubin/bitcoin,droark/bitcoin,litecoin-project/litecoin,tjps/bitcoin,CryptArc/bitcoin,digibyte/digibyte,thrasher-/litecoin,Christewart/bitcoin,andreaskern/bitcoin,GroestlCoin/bitcoin,pstratem/bitcoin,joshrabinowitz/bitcoin,lateminer/bitcoin,ahmedbodi/vertcoin,qtumproject/qtum,kazcw/bitcoin,jtimon/bitcoin,jmcorgan/bitcoin,vertcoin/vertcoin,mm-s/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,mm-s/bitcoin,achow101/bitcoin,bitcoin/bitcoin,jamesob/bitcoin,Kogser/bitcoin,namecoin/namecore,untrustbank/litecoin,particl/particl-core,vmp32k/litecoin,tecnovert/particl-core,EthanHeilman/bitcoin,Flowdalic/bitcoin,AkioNak/bitcoin,ElementsProject/elements,GroestlCoin/GroestlCoin,peercoin/peercoin,mitchellcash/bitcoin,Xekyo/bitcoin,lbryio/lbrycrd,MarcoFalke/bitcoin,ericshawlinux/bitcoin,alecalve/bitcoin,myriadteam/myriadcoin,GlobalBoost/GlobalBoost,lbryio/lbrycrd,namecoin/namecore,droark/bitcoin,GroestlCoin/GroestlCoin,qtumproject/qtum,pataquets/namecoin-core,apoelstra/bitcoin,DigitalPandacoin/pandacoin,Xekyo/bitcoin,jamesob/bitcoin,qtumproject/qtum,Christewart/bitcoin,practicalswift/bitcoin,tecnovert/particl-core,RHavar/bitcoin,h4x3rotab/BTCGPU,randy-waterhouse/bitcoin,h4x3rotab/BTCGPU,ajtowns/bitcoin,instagibbs/bitcoin,Kogser/bitcoin,litecoin-project/litecoin,Christewart/bitcoin,pataquets/namecoin-core,JeremyRubin/bitcoin,wellenreiter01/Feathercoin,prusnak/bitcoin,Kogser/bitcoin,myriadcoin/myriadcoin,RHavar/bitcoin,namecoin/namecoin-core,practicalswift/bitcoin,kazcw/bitcoin,guncoin/guncoin,CryptArc/bitcoin,sstone/bitcoin,yenliangl/bitcoin,GroestlCoin/GroestlCoin,jambolo/bitcoin,n1bor/bitcoin,sipsorcery/bitcoin,gjhiggins/vcoincore,Sjors/bitcoin,rnicoll/bitcoin,Sjors/bitcoin,gjhiggins/vcoincore,JeremyRubin/bitcoin,mitchellcash/bitcoin,GroestlCoin/bitcoin,sstone/bitcoin,GroestlCoin/bitcoin,fujicoin/fujicoin,EthanHeilman/bitcoin,rawodb/bitcoin,jmcorgan/bitcoin,nikkitan/bitcoin,namecoin/namecoin-core,n1bor/bitcoin,andreaskern/bitcoin,rnicoll/dogecoin,bitcoinsSG/bitcoin,sstone/bitcoin,OmniLayer/omnicore,alecalve/bitcoin,peercoin/peercoin,randy-waterhouse/bitcoin,litecoin-project/litecoin,ajtowns/bitcoin,gjhiggins/vcoincore,rnicoll/dogecoin,joshrabinowitz/bitcoin,untrustbank/litecoin,randy-waterhouse/bitcoin,andreaskern/bitcoin,anditto/bitcoin,litecoin-project/litecoin,Flowdalic/bitcoin,digibyte/digibyte,jambolo/bitcoin,DigitalPandacoin/pandacoin,pstratem/bitcoin,wellenreiter01/Feathercoin,OmniLayer/omnicore,tjps/bitcoin,ahmedbodi/vertcoin,domob1812/bitcoin,anditto/bitcoin,mm-s/bitcoin,GroestlCoin/GroestlCoin,apoelstra/bitcoin,jnewbery/bitcoin,rawodb/bitcoin,prusnak/bitcoin,sipsorcery/bitcoin,JeremyRubin/bitcoin,sstone/bitcoin,randy-waterhouse/bitcoin,nikkitan/bitcoin,DigitalPandacoin/pandacoin,peercoin/peercoin,namecoin/namecore,Bushstar/UFO-Project,nikkitan/bitcoin,achow101/bitcoin,litecoin-project/litecoin,bespike/litecoin,GroestlCoin/GroestlCoin,rnicoll/dogecoin,OmniLayer/omnicore,joshrabinowitz/bitcoin,kallewoof/bitcoin,bitcoin/bitcoin,CryptArc/bitcoin,Xekyo/bitcoin,jmcorgan/bitcoin,kallewoof/bitcoin,r8921039/bitcoin,bitcoin/bitcoin,bitcoinsSG/bitcoin,afk11/bitcoin,cdecker/bitcoin,jtimon/bitcoin,rawodb/bitcoin,mm-s/bitcoin,kallewoof/bitcoin,FeatherCoin/Feathercoin,Bushstar/UFO-Project,tecnovert/particl-core,pataquets/namecoin-core,ericshawlinux/bitcoin,tjps/bitcoin,rnicoll/dogecoin,n1bor/bitcoin,rnicoll/bitcoin,RHavar/bitcoin,namecoin/namecoin-core,BTCGPU/BTCGPU,jonasschnelli/bitcoin,Christewart/bitcoin,Bushstar/UFO-Project,ahmedbodi/vertcoin,digibyte/digibyte,FeatherCoin/Feathercoin,cdecker/bitcoin,midnightmagic/bitcoin,ElementsProject/elements,AkioNak/bitcoin,domob1812/namecore,ericshawlinux/bitcoin,AkioNak/bitcoin,droark/bitcoin,kallewoof/bitcoin,rawodb/bitcoin,r8921039/bitcoin,peercoin/peercoin,BTCGPU/BTCGPU,nikkitan/bitcoin,lbryio/lbrycrd,bitcoinknots/bitcoin,domob1812/bitcoin,fanquake/bitcoin,GlobalBoost/GlobalBoost,randy-waterhouse/bitcoin,apoelstra/bitcoin,qtumproject/qtum,n1bor/bitcoin,jamesob/bitcoin,jlopp/statoshi,bitcoinsSG/bitcoin,MarcoFalke/bitcoin,DigitalPandacoin/pandacoin,fanquake/bitcoin,Kogser/bitcoin,jmcorgan/bitcoin,MeshCollider/bitcoin,dscotese/bitcoin,FeatherCoin/Feathercoin,Xekyo/bitcoin,lbryio/lbrycrd,qtumproject/qtum,jlopp/statoshi,OmniLayer/omnicore,bitcoinknots/bitcoin,guncoin/guncoin,practicalswift/bitcoin,vertcoin/vertcoin,EthanHeilman/bitcoin,kazcw/bitcoin,anditto/bitcoin,thrasher-/litecoin,tecnovert/particl-core,MarcoFalke/bitcoin,MeshCollider/bitcoin,JeremyRubin/bitcoin,ElementsProject/elements,AkioNak/bitcoin,joshrabinowitz/bitcoin,vmp32k/litecoin,prusnak/bitcoin,dscotese/bitcoin,alecalve/bitcoin,domob1812/namecore,tjps/bitcoin,afk11/bitcoin,anditto/bitcoin,gjhiggins/vcoincore,nikkitan/bitcoin,wellenreiter01/Feathercoin,domob1812/bitcoin,lbryio/lbrycrd,pataquets/namecoin-core,bitcoinknots/bitcoin,apoelstra/bitcoin,monacoinproject/monacoin,vertcoin/vertcoin,myriadteam/myriadcoin,rawodb/bitcoin,tjps/bitcoin,EthanHeilman/bitcoin,guncoin/guncoin,domob1812/namecore,kallewoof/bitcoin,monacoinproject/monacoin,myriadcoin/myriadcoin,h4x3rotab/BTCGPU,mruddy/bitcoin,domob1812/namecore,cdecker/bitcoin,Xekyo/bitcoin,jambolo/bitcoin,GlobalBoost/GlobalBoost,droark/bitcoin,myriadcoin/myriadcoin,thrasher-/litecoin,untrustbank/litecoin,myriadteam/myriadcoin,jonasschnelli/bitcoin,mm-s/bitcoin,rawodb/bitcoin,GlobalBoost/GlobalBoost,pstratem/bitcoin,sipsorcery/bitcoin,thrasher-/litecoin,fanquake/bitcoin,jamesob/bitcoin,fujicoin/fujicoin,particl/particl-core,r8921039/bitcoin,pstratem/bitcoin,wellenreiter01/Feathercoin,bitcoinknots/bitcoin,untrustbank/litecoin,bitcoin/bitcoin,Flowdalic/bitcoin,guncoin/guncoin,BTCGPU/BTCGPU,tecnovert/particl-core,monacoinproject/monacoin,r8921039/bitcoin,Kogser/bitcoin,jnewbery/bitcoin,namecoin/namecore,instagibbs/bitcoin,myriadteam/myriadcoin,vmp32k/litecoin,midnightmagic/bitcoin,apoelstra/bitcoin,untrustbank/litecoin,particl/particl-core,Christewart/bitcoin,afk11/bitcoin,fujicoin/fujicoin,instagibbs/bitcoin,myriadcoin/myriadcoin,bitcoinsSG/bitcoin,GroestlCoin/GroestlCoin,jnewbery/bitcoin,jtimon/bitcoin,pstratem/bitcoin,JeremyRubin/bitcoin,ajtowns/bitcoin,instagibbs/bitcoin,nikkitan/bitcoin,digibyte/digibyte,particl/particl-core,jtimon/bitcoin,mitchellcash/bitcoin,r8921039/bitcoin,bitcoinsSG/bitcoin,Kogser/bitcoin,bespike/litecoin,ajtowns/bitcoin,CryptArc/bitcoin,RHavar/bitcoin,DigitalPandacoin/pandacoin,OmniLayer/omnicore,vertcoin/vertcoin,FeatherCoin/Feathercoin,andreaskern/bitcoin,yenliangl/bitcoin,alecalve/bitcoin,pstratem/bitcoin,vertcoin/vertcoin,jlopp/statoshi,domob1812/bitcoin,wellenreiter01/Feathercoin,Kogser/bitcoin,Sjors/bitcoin,monacoinproject/monacoin,achow101/bitcoin,Xekyo/bitcoin,practicalswift/bitcoin,domob1812/bitcoin,vmp32k/litecoin,domob1812/namecore,yenliangl/bitcoin,afk11/bitcoin,myriadteam/myriadcoin,GroestlCoin/bitcoin,prusnak/bitcoin,MeshCollider/bitcoin,CryptArc/bitcoin,bespike/litecoin,namecoin/namecore,GroestlCoin/bitcoin,Bushstar/UFO-Project,ahmedbodi/vertcoin,mruddy/bitcoin,bitcoinsSG/bitcoin,vmp32k/litecoin,dscotese/bitcoin,namecoin/namecoin-core,rnicoll/dogecoin,sstone/bitcoin,kazcw/bitcoin,guncoin/guncoin,jmcorgan/bitcoin,achow101/bitcoin,Kogser/bitcoin,jlopp/statoshi,MeshCollider/bitcoin,jnewbery/bitcoin,bitcoin/bitcoin,practicalswift/bitcoin,jonasschnelli/bitcoin,prusnak/bitcoin,alecalve/bitcoin,andreaskern/bitcoin,namecoin/namecore,fujicoin/fujicoin,qtumproject/qtum,AkioNak/bitcoin,myriadteam/myriadcoin,bespike/litecoin,CryptArc/bitcoin,instagibbs/bitcoin,rnicoll/bitcoin,fujicoin/fujicoin,namecoin/namecoin-core,midnightmagic/bitcoin,pataquets/namecoin-core,jnewbery/bitcoin,kazcw/bitcoin,myriadcoin/myriadcoin,anditto/bitcoin,FeatherCoin/Feathercoin,joshrabinowitz/bitcoin,Sjors/bitcoin,thrasher-/litecoin,lateminer/bitcoin,fanquake/bitcoin,prusnak/bitcoin,ericshawlinux/bitcoin,Kogser/bitcoin,jlopp/statoshi,mruddy/bitcoin,monacoinproject/monacoin,pataquets/namecoin-core,cdecker/bitcoin,AkioNak/bitcoin,fujicoin/fujicoin,Bushstar/UFO-Project,cdecker/bitcoin,gjhiggins/vcoincore,practicalswift/bitcoin,n1bor/bitcoin,midnightmagic/bitcoin,ahmedbodi/vertcoin,ElementsProject/elements,sipsorcery/bitcoin,Flowdalic/bitcoin,domob1812/namecore,bespike/litecoin,ericshawlinux/bitcoin,apoelstra/bitcoin,jmcorgan/bitcoin,EthanHeilman/bitcoin,jamesob/bitcoin,particl/particl-core,droark/bitcoin,tjps/bitcoin,FeatherCoin/Feathercoin,fanquake/bitcoin,rnicoll/bitcoin,RHavar/bitcoin,digibyte/digibyte,EthanHeilman/bitcoin,mm-s/bitcoin,jonasschnelli/bitcoin,instagibbs/bitcoin,h4x3rotab/BTCGPU,h4x3rotab/BTCGPU,Flowdalic/bitcoin,andreaskern/bitcoin,BTCGPU/BTCGPU,mitchellcash/bitcoin,afk11/bitcoin,monacoinproject/monacoin,h4x3rotab/BTCGPU,midnightmagic/bitcoin,bespike/litecoin,MarcoFalke/bitcoin,RHavar/bitcoin,litecoin-project/litecoin,Flowdalic/bitcoin,rnicoll/bitcoin,untrustbank/litecoin,BTCGPU/BTCGPU,fanquake/bitcoin,DigitalPandacoin/pandacoin,Christewart/bitcoin,myriadcoin/myriadcoin,wellenreiter01/Feathercoin,gjhiggins/vcoincore,ElementsProject/elements,kallewoof/bitcoin,sipsorcery/bitcoin,namecoin/namecoin-core,achow101/bitcoin,dscotese/bitcoin,lbryio/lbrycrd,Kogser/bitcoin,MarcoFalke/bitcoin,GlobalBoost/GlobalBoost,Bushstar/UFO-Project,particl/particl-core,n1bor/bitcoin,Kogser/bitcoin,jtimon/bitcoin,cdecker/bitcoin,MeshCollider/bitcoin,rnicoll/bitcoin,mruddy/bitcoin