Fix: nginx http2 Syntax für nginx 1.25+ (listen 443 ssl + http2 on)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

installer.sh

@@ -725,8 +725,9 @@ if [ -n "${UI_HOST}" ] && [ "${UI_HAS_CERT}" = "1" ]; then
   cat <<CONF
 
 server {
-  listen 443 ssl http2;
+  listen 443 ssl;
-  listen [::]:443 ssl http2;
+  listen [::]:443 ssl;
+  http2 on;
   server_name ${UI_HOST};
 
   ssl_certificate     /etc/letsencrypt/live/${UI_HOST}/fullchain.pem;
@@ -752,8 +753,9 @@ if [ -n "${WEBMAIL_HOST}" ] && [ "${WM_HAS_CERT}" = "1" ]; then
   cat <<CONF
 
 server {
-  listen 443 ssl http2;
+  listen 443 ssl;
-  listen [::]:443 ssl http2;
+  listen [::]:443 ssl;
+  http2 on;
   server_name ${WEBMAIL_HOST};
 
   ssl_certificate     /etc/letsencrypt/live/${WEBMAIL_HOST}/fullchain.pem;