if url have port in it , php will have this error

$url = "http://localhost:3000";
$response = Unirest\Request::get($url, $headers);

A PHP Error was encountered
Severity: Notice

Message: Trying to access array offset on value of type int

Filename: Unirest/Request.php

Line Number: 555

Backtrace:

File: /Users/jack/Documents/html/vendor/mashape/unirest-php/src/Unirest/Request.php
Line: 555
Function: _error_handler

File: /Users/jack/Documents/html/vendor/mashape/unirest-php/src/Unirest/Request.php
Line: 417
Function: encodeUrl

File: /Users/jack/Documents/html/vendor/mashape/unirest-php/src/Unirest/Request.php
Line: 236
Function: send