If checkIp() was able to match against array, I could simplify it to this:

    do {
        $clientIp = array_pop($clientIps);

        if (!IpUtils::checkIp($clientIp, $trustedProxy)) {
            return $clientIp;
        }
    } while ($clientIps);

But for now, since we need to check other trusted proxies in the loop, we can't return when `false === checkIp()`, and we can't return when `true === checkIp()` as well, since there may be another trusted proxy up the list. That's why I use `continue` within inner loop, and then break outer loop in case $clientIp does not match any of trusted ips.