environs/sshstorage: adjust error message
environs/sshstorage: adjust error message

Check that error includes "No such file", rather than
"No such file or directory".

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