chore: also document keepalive_timeout for nginx-root.conf

Signed-off-by: Simon L. <szaimen@e.mail.de>

Author: szaimen

admin_manual/installation/nginx-root.conf.sample

@@ -61,6 +61,7 @@ server {
 
     # Proxy and client response timeouts
     # Uncomment an increase these if facing timeout errors during large file uploads
+    #keepalive_timeout 60s;
     #proxy_connect_timeout 60s;
     #proxy_send_timeout 60s;
     #proxy_read_timeout 60s;

admin_manual/installation/nginx-subdir.conf.sample

@@ -88,6 +88,7 @@ server {
 
         # Proxy and client response timeouts
         # Uncomment an increase these if facing timeout errors during large file uploads
+        #keepalive_timeout 60s;
         #proxy_connect_timeout 60s;
         #proxy_send_timeout 60s;
         #proxy_read_timeout 60s;