Comment 2 for bug 1584792

Reviewed: https://review.openstack.org/300462
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=7a05679ebc944e3bec6f20c194c40fae1cf39d8d
Submitter: Jenkins
Branch: master

commit 7a05679ebc944e3bec6f20c194c40fae1cf39d8d
Author: James Slagle <email address hidden>
Date: Fri Apr 1 08:57:41 2016 -0400

    Show correct missing files when an error occurs

    This function was swallowing all missing file exceptions, and then
    printing a message saying overcloud.yaml or
    overcloud-without-mergepy.yaml were not found.

    The problem is that the URLError could occur for any missing file, such
    as a missing environment file, typo in a relative patch or filename,
    etc. And in those cases, the error message is actually quite misleading,
    especially if the overcloud.yaml does exist at the exact shown path.

    This change makes it such that the actual missing file paths are shown
    in the output.

    Closes-Bug: 1584792
    Change-Id: Id9a70cb50d7dfa3dde72eefe0a5eaea7985236ff