I'd like to add some custom settings such as "Strict-Transport-Security", etc. I see that in my .vhost files there is an entry, however commented out. What is the proper way to add this, just add the line in the Apache2 directives for each site, or is there a checkbox somewhere to do this? I'm also wanting to set global settings for all sites, is there a way to do this as well? Specifically changing "SSLCipherSuite", "SSLProtocol", etc.
If you want to use it by default for all sites, copy /usr/local/ispconfig/server/conf/vhost.conf.master to /usr/local/ispconfig/server/conf-custom/vhost.conf.master and modify it with your prefered settings, e.g. HSTS. After doing so, you can resync all sites to generate new configuration under Tools > Resync.