HTTP2 for non-https endpoints

[mazzz1y]

Prerequisites

• I have checked the Wiki and Discussions and found no answer

• I have searched other issues and found no duplicates

• I want to request a feature or enhancement and not ask a question

Description

What problem are you trying to solve?

http2.0 not working for non-https endpoints

~ docker run -p3000:3000 -d adguard/adguardhome:v0.107.11 
~ curl -i --http2-prior-knowledge localhost:3000
curl: (16) Send failure: Broken pipe

Working example with another golang app

~ docker run -p8080:80 -d traefik
~ curl -i --http2-prior-knowledge localhost:3000
HTTP/2 404 
content-type: text/plain; charset=utf-8
x-content-type-options: nosniff
content-length: 19
date: Mon, 19 Sep 2022 10:24:37 GMT

404 page not found

It is required for some proxy configurations to avoid downgrading to http1.1