api2/access/acl: make update_acl a protected api call

since we want to set the owner of the acl config to 'root'
which is only possible when using a protected api call

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/api2/access/acl.rs

@@ -103,6 +103,7 @@ pub fn read_acl(
 }
 
 #[api(
+    protected: true,
     input: {
         properties: {
 	    path: {