C++CURL庫的一個bug，CURLOPT_TIMEOUT_MS設置時間小於1s直接報錯

解決辦法：
This is a bug of CURL.

If your timeout setting is less than 1s, it will directly return an error.

Solution is:

curl_easy_setopt(conn, CURLOPT_NOSIGNAL, 1);
conn is the pointer of CURL, e.g.:

CURL *conn = NULL;
curl_easy_setopt(conn, CURLOPT_NOSIGNAL, 1);