Remove a mirror for a registry
Remove mirror for a given registry.
pack config registry-mirrors remove <registry> [flags]
pack config registry-mirrors remove index.docker.io
  -h, --help   help for remove
      --force-color   Force color output
      --no-color      Disable color output
  -q, --quiet         Show less output
      --timestamps    Enable timestamps in output
  -v, --verbose       Show more output