file_get_contents and simplexml_load_file are empty - php

Question

I want to read the xml from this url:
https://username:password#wetter.ws.siag.it/Weather_V1.svc/web/getLastProvBulletin?lang=de
but even when I try it with simplexml_load_file($url) I get this error:
parser error : Document is empty
And when I want to test it with file_get_contents($url) i get an empty string
""
Is it possible that this website blocks scripts? When yes, why it works with the wordpressplugin WP All import
I also tried it with curl:
private function curl($url) {
$headers[] = "User-Agent:Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13";
$headers[] = "Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
$headers[] = "Accept-Language:en-us,en;q=0.5";
$headers[] = "Accept-Encoding:gzip,deflate";
$headers[] = "Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.7";
$headers[] = "Keep-Alive:115";
$headers[] = "Connection:keep-alive";
$headers[] = "Cache-Control:max-age=0";
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curl, CURLOPT_ENCODING, "gzip");
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($curl);
curl_close($curl);
return $data;
}
... same issue