isRemote() is not the same as !isLocal()

When passing an empty string as the IP like this:
```php
$ip = '';
$is_remote = Ip::isRemote($ip);
```

it returns `true`, even thought the IP itself is invalid.

This is because `isLocal()` returns `false` (due to the IP being invalid), and `isRemote()` simply switches the result to `true`.

Workaround:
```php
$ip = '';
$is_remote = Ip::isValid($ip) && Ip::isRemote($ip);
```