fix(gitea): slow browsing on http2.

Some request had a waiting time of tens of seconds.
An issue is currently open:
go-gitea/gitea#19265

Author: MickaelGuilloux

roles/gitea/templates/etc_apache2_sites-available_gitea.conf.j2

@@ -15,6 +15,13 @@ MDomain {{ gitea_fqdn }}
 
 <VirtualHost *:443>
   ServerName  {{ gitea_fqdn }}
+
+  # This is a hack.
+  # There is a "Slow browsing on http2 enabled reverse proxy, long-polling /user/events blocks other requests"
+  # issue with Gitea.
+  # See https://github.com/go-gitea/gitea/issues/19265
+  Protocols http/1.1
+
   ServerAdmin webmaster@{{ gitea_fqdn }}
   SSLEngine on
 {% if gitea_https_mode == 'selfsigned' %}