[exim] annoyance with reverse lookup

on 4.44 I set
verify = reverse_host_lookup/defer_ok

Then it first looks up dns, which is fine,

Then it reduntantly calls gethostbyaddr() which returns EAGAIN and now
defer_ok seems like has no purpose at all

I had to set host_lookup_order to get previous behavior back.

Regards,
Andris Peize