The source project of this merge request has been removed.
copy install/tpl/apache_ispconfig.conf.master to server/conf/apache_ispconfig.conf.master
If you add/remove server IPs the file /etc/apache2/sites-available/ispconfig.conf gets recreated and it is missing the alias for Let's Encrypt ACME challenges. Copying over the current install template fixes that.
Maybe one could remove this template duplication completely by using server/conf/apache_ispconfig.conf.master in the install process?
The Header set Content-Type "text/plain" was only in server/conf/apache_ispconfig.conf.master and not in install/tpl/apache_ispconfig.conf.master – is it necessary?