Ajax Erroe

I see this Ajax error when adding subscribers via Mailpoet.

It does not appear to affect anything but this is just for your information

Object
component: “Plugin: cleantalk-spam-protect”
file: “wp-content/plugins/cleantalk-spam-protect/lib/CleantalkHelper.php”
line: 64
message: “Undefined index: X-Forwarded-For”
stack: (3) [“CleantalkHelper::ip__get()”, “apbct_base_call()”, “ct_ajax_hook()”]
type: “notice”