Avoid Ruby 2.1.0 crash due to Excon bug when connection is failed
Avoid Ruby 2.1.0 crash due to Excon bug when connection is failed

geemus/excon#358

apepper/faraday,zhaoxl/faraday,AvaelKross/faraday,stayhero/faraday,ngpestelos/faraday,mauricionr/faraday,lostisland/faraday,santiagodoldan/faraday,ru-faraon/Faraday-is-an-HTTP-client,hstrowd/faraday,O-I/faraday,davidcornu/faraday,grosser/faraday,daviswahl/faraday,zhaoxl/faraday,nevans/faraday,santiagodoldan/faraday,coinbase/faraday,ekampp/faraday,jrafanie/faraday,AvaelKross/faraday,davidcornu/faraday,ngpestelos/faraday,luvtechno/faraday,stayhero/faraday,davoclavo/faraday,coinbase/faraday,pvdb/faraday,spyofchina/faraday,iamjarvo/faraday,zanker/faraday,prcongithub/faraday,spyofchina/faraday,customink/faraday,hrysd/faraday,zanker/faraday,mehulkar/faraday,lostisland/faraday,O-I/faraday,ru-faraon/Faraday-is-an-HTTP-client,luvtechno/faraday,iamjarvo/faraday,daviswahl/faraday,mehulkar/faraday,prcongithub/faraday,engineyard/faraday,jhass/faraday,hstrowd/faraday,pvdb/faraday,flower-pot/faraday,jhass/faraday,nevans/faraday,grosser/faraday,davoclavo/faraday,ekampp/faraday,engineyard/faraday,mauricionr/faraday,flower-pot/faraday,jrafanie/faraday,customink/faraday,hrysd/faraday,apepper/faraday