Add connection timeout

src/SmsSenderUtil.php

@@ -119,6 +119,7 @@ class SmsSenderUtil
         curl_setopt($curl, CURLOPT_HEADER, 0);
         curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
         curl_setopt($curl, CURLOPT_POST, 1);
+        curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 60);
         curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($dataObj));
         curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
         curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);