add nxdomain-redirect to options grammar
add nxdomain-redirect to options grammar

I just used "string" as the value type.
There is no real order here so just put by another "nxdomain" option.
This was not reviewed.
This is for ticket #39384 which also considers other work.

each/bind9-collab,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9