is binary check should be done for all header

not only the first ones. 
Also added iso mime type
#95

Author: zyuhel

src/RequestResolvers/Curl.php

@@ -26,8 +26,8 @@ class Curl implements RequestResolverInterface
 
     public static $binaryContentTypes = [
         '#image/.*#',
-        '#application/(pdf|x-download|zip|pdf|msword|vnd\\.ms|postscript|octet-stream|ogg)#',
-        '#application/x-zip.*#',
+        '#application/(pdf|x-download|zip|pdf|msword|vnd\\.ms|postscript|octet-stream|ogg|x-iso9660-image)#',
+        '#application/x-zip.*#'
     ];
 
     /**
@@ -157,7 +157,7 @@ protected function resolve()
 
     protected function headerCallback($connection, $string)
     {
-        if (($this->isBinary === null) && strpos($string, ':')) {
+        if (strpos($string, ':')) {
             list($name, $value) = array_map('trim', explode(':', $string, 2));
 
             if (strtolower($name) === 'content-type') {