In fact, your XAMPP is using IPv6, and that's why it wasn't detected as being local.
To detect if your server is local, I compare $_SERVER['SERVER_ADDR'], which contains the IP address of the server, against 127.0.0.1, 10.0.X.X and 192.168.X.X. But, I didn't check ::1, the IPv6 equivalent of 127.0.0.1. It has been solved tuesday evening.
In fact, your XAMPP is using IPv6, and that's why it wasn't detected as being local.
To detect if your server is local, I compare $_SERVER['SERVER_ADDR'], which contains the IP address of the server, against 127.0.0.1, 10.0.X.X and 192.168.X.X. But, I didn't check ::1, the IPv6 equivalent of 127.0.0.1. It has been solved tuesday evening.