please fix proxy_use_baseurl option...

function purge_urls($purge_urls) {

foreach ($purge_urls as $purge_url) {
$purge_url_parts = parse_url($purge_url);

// Process all urls for each proxy
foreach ($proxy_configs as $proxy_config) {
// Set the base url of the proxy request (scheme + domain)
// First check if the use base url option is set
if ($proxy_config['proxy_use_baseurl']) {
$purge_base_url = $base_url_parts['scheme'] . $base_url_parts['host'];

should have :// like...

$purge_base_url = $base_url_parts['scheme']. "://" . $base_url_parts['host'];

thanks