Add switch to skip fetching certificates auto{config,discover} subdomains (#5838)

* Add ACME_DONT_FETCH_CERTS_FOR_HTTP_SUBDOMAINS to acme.sh

* Add ACME_DONT_FETCH_CERTS_FOR_HTTP_SUBDOMAINS to docker-compose.yml

* Add ACME_DONT_FETCH_CERTS_FOR_HTTP_SUBDOMAINS to generate_config.sh

* Add ACME_DONT_FETCH_CERTS_FOR_HTTP_SUBDOMAINS to update.sh

* AUTODISCOVER_SAN instead of long string

default on,
default is fetching certs for auto{discover,conf}

* AUTODISCOVER_SAN instead of long string

also flipped

* AUTODISCOVER_SAN instead of long string

flipped default meaning

* fix explanation for AUTODISCOVER_SAN

* AUTODISCOVER_SAN instead of long string

and flipped meaning of the bool

* fix AUTODISCOVER_SAN explanation

* Merge branch 'mailcow:staging' into staging

* update.sh: corrected syntax for mailcow.conf insertion