Summary

Fixes the INWX registrar provider to replace nameservers instead of merging existing and desired nameservers.

Problem

The GetRegistrarCorrections() function was merging the currently registered nameservers with the desired nameservers from the configuration. This caused nameserver updates to fail when migrating a domain from one DNS provider to another.

Example failure:
Update nameservers arely.ns.cloudflare.com,pablo.ns.cloudflare.com -> arely.ns.cloudflare.com,ns.inwx.de,ns2.inwx.de,ns3.inwx.eu,pablo.ns.cloudflare.com
FAILURE! (2306)

Solution

Changed the logic to use only the configured nameservers (dc.Nameservers) instead of creating a union with the existing registrar nameservers.

Before

combined := map[string]bool{}
for _, ns := range dc.Nameservers {
    combined[ns.Name] = true
}
for _, rs := range regNameservers {
    combined[rs] = true
}

After

var expected []string
for _, ns := range dc.Nameservers {
    expected = append(expected, ns.Name)
}