odhcpd: update to Git HEAD (2025-12-13)

odhcpd: update to Git HEAD (2025-12-13)

cf51aeb93220 odhcpd: fix captive_portal_uri reset
e8b7fdea8d5e dhcpv4: fix DNS server option
b84553e496a3 router: Modify relayed RA PIO P flag according to interface policy
da3e2a9829cc router: Modify relayed RA PIO A flags according to interface policy
bad7138b70f0 README.md: update dhcp ubus events

https://github.com/openwrt/odhcpd/compare/ca00527e5fc3...cf51aeb93220

Also remove duplicated /usr/share/libubox/jshn.sh include.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>