doc: update 'Debugging why ping was Broken in Docker Images'
doc: update 'Debugging why ping was Broken in Docker Images'

This includes an update to the `--xattrs` flag, it turns out you also
need to use `--xattrs-include=*`.

Reported-by: Florian Koch <d53ca8e401361ea670cf7e077e5534d267b39795@gmail.com>
Signed-off-by: Aleksa Sarai <b305c9b0212d6145eea67bbffd24e29cb79c759c@cyphar.com>

cyphar/cyphar.com,cyphar/cyphar.com,cyphar/cyphar.com,cyphar/cyphar.com