Remove duplicate HSTS headers from nginx.conf (#19018)

* Update nginx.conf

* Update nginx.conf

* Update nginx.conf

dist/nginx.conf

@@ -52,21 +52,19 @@ server {
   gzip_http_version 1.1;
   gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml image/x-icon;
 
-  add_header Strict-Transport-Security "max-age=31536000" always;
-
   location / {
     try_files $uri @proxy;
   }
 
   location ~ ^/(emoji|packs|system/accounts/avatars|system/media_attachments/files) {
     add_header Cache-Control "public, max-age=31536000, immutable";
-    add_header Strict-Transport-Security "max-age=31536000" always;
+    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains";
     try_files $uri @proxy;
   }
 
   location /sw.js {
     add_header Cache-Control "public, max-age=0";
-    add_header Strict-Transport-Security "max-age=31536000" always;
+    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains";
     try_files $uri @proxy;
   }
 
@@ -90,7 +88,6 @@ server {
     proxy_cache_valid 410 24h;
     proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
     add_header X-Cached $upstream_cache_status;
-    add_header Strict-Transport-Security "max-age=31536000" always;
 
     tcp_nodelay on;
   }