response 沒有content-type 的API 怎么獲取數(shù)據(jù)

對(duì)接API時(shí)，對(duì)方的API 響應(yīng)頭沒有content-type，數(shù)據(jù)是返回了，可在PHP怎么獲取呢？

附API鏈接：
https://api.huobipro.com/mark...

附PHP 代碼:

<?php 

$url = "https://api.huobipro.com/market/history/kline?AccessKeyId=5425863f-264c3daa-08865b14-81be8&SignatureMethod=HmacSHA256&SignatureVersion=2&Timestamp=2018-06-02T02%3A42%3A55&period=1min&size=150&symbol=btcusdt&Signature=WezIbDKAemjOnyIraKbHYZRl49SkthvhW%2F9Sq%2Bs4LPQ%3D";

$res = curl($url);

function curl($url) {
    var_dump($url);
    $ch = curl_init();
    curl_setopt($ch,CURLOPT_URL, $url);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
    curl_setopt($ch,CURLOPT_HEADER,0);
    curl_setopt($ch, CURLOPT_TIMEOUT,60);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);  
    curl_setopt ($ch, CURLOPT_HTTPHEADER, [
        "Content-Type: application/json",
        ]);
    $output = curl_exec($ch);
    $info = curl_getinfo($ch);
    var_dump($info);
    curl_close($ch);
    var_dump($output); // 這打印是false

    return $output;
}

但在瀏覽器訪問是正常打開的，需要哪設(shè)置下？