luci-app-ddns: 'bind network' list doesn't let choosing `wan6` for IPv6 client

[dmig]

Steps to reproduce:

1. Go to: Service → DynamicDNS
2. Create new service record for: IPv6-Address, no-ip.com
3. Fill all basic settings, go to Advanced settings
4. Set 'IP address source' to 'URL'
5. Set 'URL to detect' to 'http://checkipv6.dyndns.com'
6. In the 'Bind network' list 2 options are available: lan and wan (wan, wan6) (my case) -- choose wan as it assumes both IPv4 and IPv6
7. Save and run client

Actual behavior:

Service fails:

...
092205  info : Starting main loop at 2023-05-28 09:22
 092206       : Detect local IP on 'web'
 092206 ERROR : Can not detect local IP using 'network_get_ipaddr6 wan' - Error: '1' - TERMINATE
 092206  WARN : PID '4527' exit WITH ERROR '1' at 2023-05-28 09:22

Expected behavior:

Service renews IPv6 successfully

Workaround:

Set 'Bind network' to wan6 manually or execute:

uci set ddns.myddns_ipv6.bind_network=wan6

Additional Information:

DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='22.03.3'
DISTRIB_REVISION='r20028-43d71ad93e'
DISTRIB_TARGET='ramips/mt7620'
DISTRIB_ARCH='mipsel_24kc'
DISTRIB_DESCRIPTION='OpenWrt 22.03.3 r20028-43d71ad93e'
DISTRIB_TAINTS=''

# opkg info luci-app-ddns
Package: luci-app-ddns
Version: git-23.118.79498-4390b4d

[Deeppjp116]

Hello Deep,

I'm interested in working on this issue. Could you please provide more details about the problem? Additionally, I would like to know how I can set up this repository on my computer.

Thank you!