Resolve exception handling when tor file missing
Resolve exception handling when tor file missing

When running on Tails under a python2 virtualenv I was unable to catch the
exception until I added EnvironmentError in the mix. IOError was not catching
it for some reason. Until this was added in the script was failing for me when
either ssh-aths file was missing.

ageis/securedrop,garrettr/securedrop,garrettr/securedrop,conorsch/securedrop,micahflee/securedrop,ageis/securedrop,heartsucker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,heartsucker/securedrop,ageis/securedrop,ageis/securedrop,conorsch/securedrop,ehartsuyker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,garrettr/securedrop,conorsch/securedrop,micahflee/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,micahflee/securedrop,conorsch/securedrop,conorsch/securedrop