Router Adv DNSSL option should be an array

[sshambar]

RFC 8106 section 5.2 defines option 31 as an array of domain names, but src/dhcpcd-definitions.conf:424 has:
embed domain search
so when an array of domains is received in a RA, the server issues the error:
dhcp_envoption 31.0/2: Invalid argument

Changing line 424 to:
embed array domain search
results in correct handling of the search list.

Really easy fix :)

[rsmarples]

Thanks for the fix!