provider/local: fix syscall.ECONNREFUSED detection
provider/local: fix syscall.ECONNREFUSED detection

Go 1.5 has changed the type of the error message returned, basically
added another level of indirection.

Altoros/juju-cloudsigma,mhilton/juju,mikemccracken/juju,mhilton/juju-juju,bac/juju,mjs/juju,dimitern/juju,makyo/juju,alesstimec/juju,fwereade/juju,macgreagoir/juju,anastasiamac/juju,alesstimec/juju,dooferlad/juju,dimitern/juju,anastasiamac/juju,ericsnowcurrently/juju,frankban/juju-tmp,fwereade/juju,tasdomas/juju,mjs/juju,tasdomas/juju,bogdanteleaga/juju,perrito666/juju,anastasiamac/juju,bz2/juju,reedobrien/juju,mjs/juju,kat-co/juju,howbazaar/juju,macgreagoir/juju,howbazaar/juju,dooferlad/juju,anastasiamac/juju,axw/juju,macgreagoir/juju,voidspace/juju,perrito666/juju,kat-co/juju,tasdomas/juju,gabriel-samfira/juju,bogdanteleaga/juju,AdamIsrael/juju,ericsnowcurrently/juju,gabriel-samfira/juju,mhilton/juju-juju,AdamIsrael/juju,axw/juju,reedobrien/juju,bogdanteleaga/juju,marcmolla/juju,bac/juju,axw/juju,wwitzel3/juju,dimitern/juju,davecheney/juju,waigani/juju,tych0/juju,cloud-green/juju,waigani/juju,bac/juju,cherylj/juju,frankban/juju,macgreagoir/juju,marcmolla/juju,AdamIsrael/juju,wwitzel3/juju,AdamIsrael/juju,gabriel-samfira/juju,mhilton/juju,anastasiamac/juju,tasdomas/juju,voidspace/juju,axw/juju,howbazaar/juju,tsakas/juju,mhilton/juju,ericsnowcurrently/juju,kat-co/juju,wwitzel3/juju,reedobrien/juju,gabriel-samfira/juju,fwereade/juju,mjs/juju,gabriel-samfira/juju,tsakas/juju,ericsnowcurrently/juju,davecheney/juju,mikemccracken/juju,kat-co/juju,makyo/juju,mjs/juju,perrito666/juju,cloud-green/juju,cherylj/juju,dooferlad/juju,mjs/juju,dooferlad/juju,tsakas/juju,mjs/juju,makyo/juju,ericsnowcurrently/juju,fwereade/juju,alesstimec/juju,davecheney/juju,bz2/juju,Altoros/juju-cloudsigma,frankban/juju-tmp,cloud-green/juju,perrito666/juju,thomnico/juju,Altoros/juju-cloudsigma,frankban/juju-tmp,reedobrien/juju,marcmolla/juju,cherylj/juju,mhilton/juju-juju,alesstimec/juju,marcmolla/juju,cloud-green/juju,cherylj/juju,thomnico/juju,frankban/juju,bz2/juju,dimitern/juju,bac/juju,makyo/juju,tych0/juju,frankban/juju,davecheney/juju,frankban/juju,dooferlad/juju,dimitern/juju,mikemccracken/juju,waigani/juju,macgreagoir/juju,kat-co/juju,voidspace/juju,thomnico/juju,bz2/juju,tych0/juju,frankban/juju,bz2/juju,waigani/juju,axw/juju,bac/juju,wwitzel3/juju,thomnico/juju,Altoros/juju-cloudsigma,voidspace/juju,frankban/juju-tmp,howbazaar/juju,reedobrien/juju,alesstimec/juju,mhilton/juju-juju,mhilton/juju,tsakas/juju,bogdanteleaga/juju,perrito666/juju,tych0/juju,mikemccracken/juju,marcmolla/juju,howbazaar/juju,mikemccracken/juju