[Minor] HTTP/2 support is enabled in proxy_host even when the checkbox is off.

[Encephala]

Checklist

• Have you pulled and found the error with jc21/nginx-proxy-manager:latest docker image?
  • Yes
• Are you sure you're not using someone else's docker image?
  • Yes
• Have you searched for similar issues (both open and closed)?
  • Yes

Describe the bug

When creating a proxy host with HTTP/2 support disabled, the listen-directive still looks as follows:
listen 443 ssl http2;

I tried to look through the source code, but in the _listen.conf file, but that does have the {% if http2_support %}-part. so I guess the variable http2_support isn't set properly. I don't quite understand where that variable is set or used in the code (in nginx.js?), so I can't submit a PR.

Nginx Proxy Manager Version

Version 2.9.19 (specifically, the Docker image that has tag 2).

To Reproduce
Steps to reproduce the behavior:

1. Create a new proxy host
2. Ensure HTTP/2 support is off
3. Examine the file at /data/nginx/proxy_host/ and note how http2 is still present in the listen directive.

Expected behavior

http2 is not present in the directive.

Screenshots

Operating System

Ubuntu 22.04 LTS.

Additional context

[Pcject]

Just replace /app/templates/_listen.conf by :
listen 80;
{% if ipv6 -%}
listen [::]:80;
{% else -%}
#listen [::]:80;
{% endif %}
{% if certificate -%}
listen 443 ssl{% if http2_support == 1 or http2_support == true %} http2{% endif %};
{% if ipv6 -%}
listen [::]:443 ssl{% if http2_support == 1 or http2_support == true %} http2{% endif %};
{% else -%}
#listen [::]:443;
{% endif %}
{% endif %}
server_name {{ domain_names | join: " " }};

[Encephala]

Looks good (but I haven't tested it), thanks for figuring it out :)

[github-actions]

Issue is now considered stale. If you want to keep it open, please comment 👍

[Encephala]

This has been fixed in #3377