Don't poll showmyip.com, it doesn't exist anymore
Don't poll showmyip.com, it doesn't exist anymore

Fixes #4679.

This leaves us with only one candidate, checkip.dyndns.org.
GetMyExternalIP should be phased out as soon as possible.

Rebased-From: c33b983

schinzelh/dash,cerebrus29301/crowncoin,keesdewit82/LasVegasCoin,BlockchainTechLLC/3dcoin,PIVX-Project/PIVX,ArgonToken/ArgonToken,xuyangcn/opalcoin,litecoin-project/bitcoinomg,cerebrus29301/crowncoin,coinkeeper/2015-06-22_19-07_digitalcoin,bickojima/bitzeny,rdqw/sscoin,nmarley/dash,keesdewit82/LasVegasCoin,pelorusjack/BlockDX,ionomy/ion,pelorusjack/BlockDX,bmp02050/ReddcoinUpdates,ahmedbodi/test2,benzmuircroft/REWIRE.io,rsdevgun16e/energi,bickojima/bitzeny,projectinterzone/ITZ,keesdewit82/LasVegasCoin,biblepay/biblepay,pinkevich/dash,schinzelh/dash,inkvisit/sarmacoins,alejandromgk/Lunar,inkvisit/sarmacoins,ZiftrCOIN/ziftrcoin,mastercoin-MSC/mastercore,blood2/bloodcoin-0.9,freelion93/mtucicoin,basicincome/unpcoin-core,HeliumGas/helium,alejandromgk/Lunar,HeliumGas/helium,ticclassic/ic,mastercoin-MSC/mastercore,Darknet-Crypto/Darknet,midnight-miner/LasVegasCoin,world-bank/unpay-core,coinerd/krugercoin,Anoncoin/anoncoin,skaht/bitcoin,kbccoin/kbc,projectinterzone/ITZ,coinkeeper/2015-06-22_19-00_ziftrcoin,48thct2jtnf/P,reddcoin-project/reddcoin,LIMXTEC/DMDv3,ColossusCoinXT/ColossusCoinXT,cryptodev35/icash,crowning-/dash,ivansib/sib16,Darknet-Crypto/Darknet,mycointest/owncoin,alejandromgk/Lunar,reddcoin-project/reddcoin,keesdewit82/LasVegasCoin,nightlydash/darkcoin,terracoin/terracoin,litecoin-project/bitcoinomg,nmarley/dash,mobicoins/mobicoin-core,jmgilbert2/energi,dashpay/dash,puticcoin/putic,Vsync-project/Vsync,jmgilbert2/energi,dev1972/Satellitecoin,coinkeeper/2015-06-22_18-36_darkcoin,crowning-/dash,zenywallet/bitzeny,dashpay/dash,ionomy/ion,LIMXTEC/DMDv3,pelorusjack/BlockDX,coinkeeper/2015-06-22_19-07_digitalcoin,ahmedbodi/test2,nightlydash/darkcoin,knolza/gamblr,Earlz/renamedcoin,putinclassic/putic,presstab/PIVX,blood2/bloodcoin-0.9,axelxod/braincoin,Earlz/renamedcoin,axelxod/braincoin,ColossusCoinXT/ColossusCoinXT,Anoncoin/anoncoin,DGCDev/digitalcoin,dmrtsvetkov/flowercoin,lakepay/lake,Darknet-Crypto/Darknet,axelxod/braincoin,lakepay/lake,PIVX-Project/PIVX,ionomy/ion,lakepay/lake,DGCDev/argentum,ZiftrCOIN/ziftrcoin,antcheck/antcoin,thelazier/dash,coinkeeper/2015-06-22_19-07_digitalcoin,mycointest/owncoin,joroob/reddcoin,presstab/PIVX,RyanLucchese/energi,schinzelh/dash,terracoin/terracoin,reddink/reddcoin,knolza/gamblr,benzmuircroft/REWIRE.io,puticcoin/putic,GroundRod/anoncoin,skaht/bitcoin,mycointest/owncoin,diggcoin/diggcoin,mobicoins/mobicoin-core,mobicoins/mobicoin-core,ionomy/ion,ediston/energi,Anoncoin/anoncoin,RyanLucchese/energi,cryptodev35/icash,GroundRod/anoncoin,bickojima/bitzeny,ticclassic/ic,biblepay/biblepay,putinclassic/putic,blood2/bloodcoin-0.9,zenywallet/bitzeny,rdqw/sscoin,crowning2/dash,DGCDev/argentum,antcheck/antcoin,freelion93/mtucicoin,midnight-miner/LasVegasCoin,slingcoin/sling-market,LIMXTEC/DMDv3,schinzelh/dash,alejandromgk/Lunar,Bloom-Project/Bloom,rdqw/sscoin,joroob/reddcoin,48thct2jtnf/P,basicincome/unpcoin-core,nightlydash/darkcoin,PIVX-Project/PIVX,willwray/dash,mobicoins/mobicoin-core,mastercoin-MSC/mastercore,reddink/reddcoin,projectinterzone/ITZ,rsdevgun16e/energi,dashpay/dash,pinkevich/dash,nightlydash/darkcoin,LIMXTEC/DMDv3,terracoin/terracoin,Petr-Economissa/gvidon,DGCDev/digitalcoin,npccoin/npccoin,ionomy/ion,dmrtsvetkov/flowercoin,greencoin-dev/digitalcoin,litecoin-project/bitcoinomg,dev1972/Satellitecoin,putinclassic/putic,DMDcoin/Diamond,benzmuircroft/REWIRE.io,biblepay/biblepay,DGCDev/digitalcoin,benzmuircroft/REWIRE.io,HeliumGas/helium,Mrs-X/Darknet,cerebrus29301/crowncoin,joroob/reddcoin,UdjinM6/dash,midnight-miner/LasVegasCoin,dev1972/Satellitecoin,dexX7/mastercore,pinkevich/dash,48thct2jtnf/P,willwray/dash,lakepay/lake,ArgonToken/ArgonToken,thelazier/dash,biblepay/biblepay,DMDcoin/Diamond,blood2/bloodcoin-0.9,antcheck/antcoin,reddink/reddcoin,ColossusCoinXT/ColossusCoinXT,thelazier/dash,worldbit/worldbit,ivansib/sibcoin,mycointest/owncoin,DMDcoin/Diamond,reddcoin-project/reddcoin,ediston/energi,ArgonToken/ArgonToken,slingcoin/sling-market,antcheck/antcoin,Vsync-project/Vsync,dmrtsvetkov/flowercoin,knolza/gamblr,UdjinM6/dash,ZiftrCOIN/ziftrcoin,benzmuircroft/REWIRE.io,reddcoin-project/reddcoin,UdjinM6/dash,HeliumGas/helium,ediston/energi,slingcoin/sling-market,Earlz/renamedcoin,putinclassic/putic,thelazier/dash,Mrs-X/Darknet,GroundRod/anoncoin,pinkevich/dash,DGCDev/argentum,greencoin-dev/digitalcoin,world-bank/unpay-core,cerebrus29301/crowncoin,Mrs-X/PIVX,skaht/bitcoin,aspirecoin/aspire,coinkeeper/2015-06-22_19-00_ziftrcoin,crowning2/dash,greencoin-dev/digitalcoin,bmp02050/ReddcoinUpdates,dashpay/dash,joroob/reddcoin,rdqw/sscoin,slingcoin/sling-market,diggcoin/diggcoin,Darknet-Crypto/Darknet,coinkeeper/2015-06-22_19-00_ziftrcoin,Bloom-Project/Bloom,diggcoin/diggcoin,pelorusjack/BlockDX,bmp02050/ReddcoinUpdates,48thct2jtnf/P,dashpay/dash,kbccoin/kbc,crowning-/dash,schinzelh/dash,nmarley/dash,axelxod/braincoin,presstab/PIVX,LIMXTEC/DMDv3,lakepay/lake,grumpydevelop/singularity,ivansib/sib16,DGCDev/digitalcoin,basicincome/unpcoin-core,bickojima/bitzeny,ahmedbodi/test2,coinerd/krugercoin,antcheck/antcoin,knolza/gamblr,willwray/dash,BlockchainTechLLC/3dcoin,RyanLucchese/energi,CoinProjects/AmsterdamCoin-v4,midnight-miner/LasVegasCoin,Petr-Economissa/gvidon,Earlz/renamedcoin,cryptodev35/icash,PandaPayProject/PandaPay,Petr-Economissa/gvidon,CoinProjects/AmsterdamCoin-v4,npccoin/npccoin,mycointest/owncoin,Vsync-project/Vsync,DGCDev/digitalcoin,projectinterzone/ITZ,bmp02050/ReddcoinUpdates,cerebrus29301/crowncoin,coinkeeper/2015-06-22_19-00_ziftrcoin,xuyangcn/opalcoin,rsdevgun16e/energi,willwray/dash,grumpydevelop/singularity,diggcoin/diggcoin,mastercoin-MSC/mastercore,BlockchainTechLLC/3dcoin,inkvisit/sarmacoins,willwray/dash,DGCDev/argentum,ivansib/sibcoin,ivansib/sib16,presstab/PIVX,inkvisit/sarmacoins,Earlz/renamedcoin,LIMXTEC/DMDv3,world-bank/unpay-core,ivansib/sib16,greencoin-dev/digitalcoin,ivansib/sibcoin,RyanLucchese/energi,xuyangcn/opalcoin,pelorusjack/BlockDX,litecoin-project/bitcoinomg,48thct2jtnf/P,reddink/reddcoin,jmgilbert2/energi,benzmuircroft/REWIRE.io,skaht/bitcoin,Mrs-X/PIVX,ediston/energi,xuyangcn/opalcoin,ticclassic/ic,freelion93/mtucicoin,thelazier/dash,jmgilbert2/energi,Bloom-Project/Bloom,grumpydevelop/singularity,basicincome/unpcoin-core,pinkevich/dash,presstab/PIVX,aspirecoin/aspire,zenywallet/bitzeny,ediston/energi,zenywallet/bitzeny,ticclassic/ic,DGCDev/argentum,coinerd/krugercoin,CoinProjects/AmsterdamCoin-v4,rsdevgun16e/energi,HeliumGas/helium,CoinProjects/AmsterdamCoin-v4,ColossusCoinXT/ColossusCoinXT,reddink/reddcoin,puticcoin/putic,RyanLucchese/energi,PIVX-Project/PIVX,dexX7/mastercore,PIVX-Project/PIVX,Mrs-X/PIVX,bmp02050/ReddcoinUpdates,DMDcoin/Diamond,skaht/bitcoin,ticclassic/ic,dmrtsvetkov/flowercoin,biblepay/biblepay,ZiftrCOIN/ziftrcoin,CoinProjects/AmsterdamCoin-v4,dmrtsvetkov/flowercoin,dexX7/mastercore,PIVX-Project/PIVX,Mrs-X/PIVX,UdjinM6/dash,crowning-/dash,ArgonToken/ArgonToken,ZiftrCOIN/ziftrcoin,aspirecoin/aspire,Petr-Economissa/gvidon,worldbit/worldbit,ionomy/ion,knolza/gamblr,Mrs-X/Darknet,RyanLucchese/energi,ticclassic/ic,presstab/PIVX,Anoncoin/anoncoin,ediston/energi,cryptodev35/icash,worldbit/worldbit,GroundRod/anoncoin,cryptodev35/icash,nmarley/dash,nmarley/dash,xuyangcn/opalcoin,mastercoin-MSC/mastercore,diggcoin/diggcoin,PandaPayProject/PandaPay,dmrtsvetkov/flowercoin,puticcoin/putic,PandaPayProject/PandaPay,slingcoin/sling-market,projectinterzone/ITZ,blood2/bloodcoin-0.9,Mrs-X/PIVX,terracoin/terracoin,grumpydevelop/singularity,bickojima/bitzeny,worldbit/worldbit,coinkeeper/2015-06-22_18-36_darkcoin,reddcoin-project/reddcoin,rdqw/sscoin,48thct2jtnf/P,npccoin/npccoin,biblepay/biblepay,Petr-Economissa/gvidon,Bloom-Project/Bloom,Bloom-Project/Bloom,jmgilbert2/energi,joroob/reddcoin,Darknet-Crypto/Darknet,Vsync-project/Vsync,ivansib/sib16,PIVX-Project/PIVX,reddcoin-project/reddcoin,midnight-miner/LasVegasCoin,pinkevich/dash,diggcoin/diggcoin,mycointest/owncoin,ArgonToken/ArgonToken,axelxod/braincoin,slingcoin/sling-market,Mrs-X/Darknet,coinkeeper/2015-06-22_18-36_darkcoin,jmgilbert2/energi,midnight-miner/LasVegasCoin,aspirecoin/aspire,aspirecoin/aspire,coinkeeper/2015-06-22_19-00_ziftrcoin,dev1972/Satellitecoin,nmarley/dash,freelion93/mtucicoin,npccoin/npccoin,cerebrus29301/crowncoin,nmarley/dash,biblepay/biblepay,dexX7/mastercore,PandaPayProject/PandaPay,inkvisit/sarmacoins,DMDcoin/Diamond,alejandromgk/Lunar,Mrs-X/PIVX,coinkeeper/2015-06-22_18-36_darkcoin,nightlydash/darkcoin,crowning2/dash,greencoin-dev/digitalcoin,biblepay/biblepay,worldbit/worldbit,terracoin/terracoin,npccoin/npccoin,PIVX-Project/PIVX,Vsync-project/Vsync,inkvisit/sarmacoins,rdqw/sscoin,ivansib/sibcoin,coinkeeper/2015-06-22_18-36_darkcoin,ivansib/sibcoin,knolza/gamblr,BlockchainTechLLC/3dcoin,ColossusCoinXT/ColossusCoinXT,ArgonToken/ArgonToken,Mrs-X/Darknet,schinzelh/dash,PandaPayProject/PandaPay,Anoncoin/anoncoin,crowning2/dash,mobicoins/mobicoin-core,putinclassic/putic,basicincome/unpcoin-core,dev1972/Satellitecoin,alejandromgk/Lunar,PandaPayProject/PandaPay,ivansib/sibcoin,crowning-/dash,freelion93/mtucicoin,grumpydevelop/singularity,aspirecoin/aspire,terracoin/terracoin,Mrs-X/Darknet,putinclassic/putic,grumpydevelop/singularity,npccoin/npccoin,Vsync-project/Vsync,ahmedbodi/test2,crowning2/dash,lakepay/lake,willwray/dash,freelion93/mtucicoin,keesdewit82/LasVegasCoin,DMDcoin/Diamond,pelorusjack/BlockDX,PIVX-Project/PIVX,puticcoin/putic,BlockchainTechLLC/3dcoin,ahmedbodi/test2,antcheck/antcoin,worldbit/worldbit,zenywallet/bitzeny,coinkeeper/2015-06-22_19-07_digitalcoin,ColossusCoinXT/ColossusCoinXT,rsdevgun16e/energi,axelxod/braincoin,coinkeeper/2015-06-22_19-07_digitalcoin,world-bank/unpay-core,kbccoin/kbc,HeliumGas/helium,Darknet-Crypto/Darknet,crowning-/dash,world-bank/unpay-core,UdjinM6/dash,BlockchainTechLLC/3dcoin,rsdevgun16e/energi,dev1972/Satellitecoin,Bloom-Project/Bloom,Petr-Economissa/gvidon,kbccoin/kbc,kbccoin/kbc,CoinProjects/AmsterdamCoin-v4,coinerd/krugercoin,ivansib/sib16,xuyangcn/opalcoin,keesdewit82/LasVegasCoin,GroundRod/anoncoin,ahmedbodi/test2,puticcoin/putic