fix: disable IPv6 binding in Nginx and increase buffers

nginx.template.conf

@@ -22,8 +22,7 @@ http {
     server_names_hash_bucket_size 128; # this seems to be required for some vhosts
 
     server {
-        listen ${PORT};
-        listen [::]:${PORT};
+        listen 0.0.0.0:${PORT};
         server_name localhost;
 
         $if(NIXPACKS_PHP_ROOT_DIR) (
@@ -65,9 +64,10 @@ http {
             include $!{nginx}/conf/fastcgi.conf;
 
             # --- CUSTOM: INCREASE BUFFERS TO FIX 502 BAD GATEWAY ---
-            fastcgi_buffers 16 32k;
+            fastcgi_buffers 64 32k;
             fastcgi_buffer_size 64k;
             fastcgi_busy_buffers_size 64k;
+            fastcgi_max_temp_file_size 0;
         }
      
         location ~ /\.(?!well-known).* {