The 'Domain-List' value should be string

As described in https://tools.ietf.org/html/rfc1035#section-3.1

Domain names in messages are expressed in terms of a sequence of labels.
Each label is represented as a one octet length field followed by that
number of octets.  Since every domain name ends with the null label of
the root, a domain name is terminated by a length byte of zero.

i.e: It should be encoded as a 'dns_label' to append the '\0'

share/dictionary/dhcpv6/dictionary.rfc3646

@@ -12,4 +12,4 @@
 ##############################################################################
 
 ATTRIBUTE	DNS-Servers				23	ipv6addr array
-ATTRIBUTE	Domain-List				24	octets		# Domain name list (DNS encoding)
+ATTRIBUTE	Domain-List				24	string array,encode=dns_label	# Domain name list (DNS encoding)