Invalid DHCPv4 and DHCPv6 configurations

There is a warning in the dhcp4 and dhcpv6 images about extraneous commas:

dhcpv4:

2023-09-27 08:19:22.821 WARN  [kea-dhcp4.dhcp4/8.139944518145552] DHCP4_CONFIG_SYNTAX_WARNING configuration syntax warning: /etc/kea/kea-dhcp4.conf:36.35: Extraneous comma. A piece of configuration may have been omitted.

dhcpv6:

2023-09-27 08:30:38.758 WARN  [kea-dhcp6.dhcp6/8.140360004474784] DHCP6_CONFIG_SYNTAX_WARNING configuration syntax warning: /etc/kea/kea-dhcp6.conf:37.35: Extraneous comma. A piece of configuration may have been omitted.