LetsEncrypt default domain
When attempting to use LetsEncrypt on a domain with an aliasdomain letsencrypt attempts to create a certificate for the alias (which then fails).
When multiple alias domains are used these are selected alphabetically.
Certificates should be issued to the default domain, or, provide a way of selecting which domain should be secured via LetsEncrypt as per SSL tab.
ISPConfig issues the certificate to the default domain and then adds the other domains already, but LE does not always care about the domain order. Only the new certbot client has a --cert-name option which might help here, but the original letsencrypt client has no such option so when LE starts to resort the order of domains on its own, then a different name might be used for the cert name. We will add sme code to ISPConfig to find the cert name for older LE clients as described in this feature request. #4612