DNS provider incorrectly inherited from verified domains in multi-provider setup

[ferranbonas]

Issue Description:
When using multiple DNS providers (e.g. GoDaddy and Cloudflare) in a single certificate request, if the first domain is already verified, its DNS provider incorrectly "cascades" to the next unverified domain.

Steps to reproduce:

1. Have a valid cert with multiple domains using different DNS providers:

   • domain1.com using dns_gd (GoDaddy)
   • domain2.com using dns_cf (Cloudflare)
     [etc]

2. When the cert is renewed:

   • domain1.com is marked as "verified_ok"
   • The code skips validation for domain1.com
   • But domain2.com incorrectly inherits dns_gd provider instead of using its dns_cf

Current behavior:

• DNS provider from verified domains "cascades" to next unverified domain
• Results in validation failures as wrong DNS provider is used

Expected behavior:

• Each domain should maintain its own DNS provider mapping
• Skipping verified domains should not affect DNS provider assignment for remaining domains

Suggested fixes:

1. Maintain DNS provider mapping separately from verification state

2. Don't increment alias_index when skipping verified domains

[Neilpang]

I tried with 2 of my domains with 2 different dns providers, but it works for me as expected.

Can you please provide with --debug 2 log?

first generate a cert with 2 domains:

acme.sh --issue  -d domain1.com  --dns dns_1   -d domain2.com  --dns dns_2  

second generate a cert with the second domain only:

acme.sh --issue -d  domain2.com  --dns dns_2

It should be passing without any validation, because the domain2.com was just verified.

third deacivate the second domain, so that the second domain will be verified next time.

acme.sh --deactivae  -d domain2.com

OK, renew the first cert:

acme.sh  --renew -d domain1.com  --force  --debug 2