qemu_opts_parse() interprets "no" as negated empty key. Consistent
with its acceptance of empty keys elsewhere, whatever that's worth.
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-2-git-send-email-armbru@redhat.com>