Failure when a configuration file is not accessible for permission reason

[reech-jeanphilippe]

When used in a sandboxed environment, the lack of permission on a configuration file leads to an error.

My use-case is Traefik running as a sandboxed systemd service, using Lego for Lets Encrypt TLS certificates generation.
When using the OVH provider, which uses this module, I have an error regarding permission on /home/traefik/.ovh.conf:

cannot get ACME client ovh: cannot load configuration: open /home/traefik/.ovh.conf: permission denied

The home directory is not accessible (ProtectHome=true), thus the loadConfig method produce an error, even using the ini.LooseLoad method.

This behaviour seems to have been introduced in this commit: 39b6ccfa1451f02114c45cd6abce2d0879a4da4f