Manual update for Nginx http/2

Hi folks,

this is my first post here so i’ll start with a big thx for this project. Actually I use 3 pi’s with pi-hole+wireguard, mattermost and nextcloud and all with diet-pi, keep it simple and thx for the time savings. My nextcloud setup was finished with everthing in under 30 min.

I want to notice that all Nginx / certbot relevant projects, could have a reminder in their discription how to enable http/2 if port 443 and SSL would be configured. I think it is a huge performance boost, and not everyone who use auto-install scripts has this feature on their mind.