Resolve "Crontab deletion after website removal"

See merge request ispconfig/ispconfig3!1069

- disallow several folders for vhost subdomains and aliasdomains

See merge request ispconfig/ispconfig3!1067

Resolve "MariaDB: Field 'nginx_directives' doesn't have a default value"

See merge request ispconfig/ispconfig3!1070

Resolve "Directories of sub- or aliasdomains (vhost) owned by root"

See merge request ispconfig/ispconfig3!1066

Resolve "mailman images not showing [nginx fix]"

See merge request ispconfig/ispconfig3!1065

change cc and sender_cc column type

See merge request ispconfig/ispconfig3!1052

Resolve "IDN encode domains in Rspamd config file names"

See merge request ispconfig/ispconfig3!1062

Resolve "Enable logging for acme.sh"

See merge request !1063

Resolve "Improve FCGI starter scripts"

See merge request !1064

Db remote server & dns slave fix

See merge request ispconfig/ispconfig3!863

# Conflicts:
#   install/sql/incremental/upd_dev_collection.sql

This reverts commit 0d61c249

Show (disabled) client field on mail_domain edit for admin

See merge request ispconfig/ispconfig3!1061

This reverts merge request !1033

Always enable HTTP/2 if available

See merge request ispconfig/ispconfig3!1033

Check if we actually have a service enabled

See merge request ispconfig/ispconfig3!1059

Extended client delete dialog (Implements #4370)

See merge request !1060

# Conflicts:
#   install/sql/incremental/upd_dev_collection.sql