We did the same sanity cleanup for all other code.  Easier on the
eyes and easier to fork.  ;)

Discussed with: ad@

Submitted by: Liu

Injecting `--' into the command line is rather funny as it stops
parsing of all following options and treats them as literals, which
dnsmasq then loudly complains about like `ain't nobody got time for
that'.

When the target has no entries at all, it doesn't know how to merge.