Bug#918502: golang-github-opencontainers-runtime-tools: autopkgtest needs update for new version of golang-github-hashicorp-go-multierror

[Arnaud Rebillout]

Thanks for the report,

I'm looking into that. The FTBFS is not fixed by updating
opencontainers-runtime-tools to the latest version (0.8).

Actually, the issue is that opencontainers-runtime-tools is using an
outdated vendored copy of hashicorp-go-multierror. It doesn't build out
of the box against the latest version of multierror. I'm cooking a
little patch for that to work.