acme-acmesh + acme-acmesh-dnsapi + luci-app-acme, can't use dns authentication method.

Maintainer: @\tohojo
Environment: ARMv7 Processor rev 5 (v7l), AVM FRITZ!Box 7530, pq40xx/generic, OpenWrt 23.05.0-rc3

Description:
If I attempt to create an ACME configuration with dns authentication, it seems to be ignored and acme.sh is launched without necessary parameters:

With luci interface I generated following config file:

config acme
	option account_email 'notify@example.com'
	option debug '1'

config cert 'Router'
	option enabled '1'
	option staging '1'
	option use_staging '0'
	option keylength '2048'
	option update_uhttpd '1'
	option validation_method 'dns'
	option dns 'dns_ovh'
	list credentials 'OVH_AK="xxxxxxxxxx"'
	list credentials 'OVH_AS="xxxxxxxxxx"'
	list credentials 'OVH_CK="xxxxxxxxxx"'
	list domains 'domain.example.com'

options validation_method and dns seems to be consistent with acme package documentation https://openwrt.org/docs/guide-user/services/tls/acmesh .

By launching /etc/init.d/acme start I obtain:

acme-acmesh: Running ACME for avm.comunifvg.ovh
acme-acmesh: /usr/lib/acme/client/acme.sh --debug --renew --home /etc/acme -d domain.example.com

If I launch acme.sh manually with correct parameters, as for example

#!/bin/bash
export OVH_AK="xxxxxxxxxx"
export OVH_AS="xxxxxxxxxx"
export OVH_CK="xxxxxxxxxx"
/usr/lib/acme/client/acme.sh --issue -i -d domain.example.com --dns dns_ovh --server letsencrypt

certificates are created correctly.

Start with the ACME configuration shown in the issue and inspect /etc/init.d/acme, focusing on how validation_method, dns, and credentials are translated into the /usr/lib/acme/client/acme.sh invocation. Compare the generated command with the working manual command; done means DNS authentication parameters are passed when the configuration uses validation_method 'dns' and dns 'dns_ovh'.