Simplify and fix image proxy

public/typo3conf/ext/ep_theme/extimg.php

@@ -36,22 +36,7 @@ if ($hash !== $token) {
     die('Access denied');
 }
 
-$ch = curl_init();
-curl_setopt($ch, CURLOPT_URL, $url);
-curl_setopt($ch, CURLOPT_TIMEOUT, 5);
-curl_setopt($ch, CURLOPT_HEADER, 1);
-curl_setopt($ch, CURLOPT_NOBODY, 1);
-curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
-curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
-$headers = curl_exec($ch);
-
-if ($headers === false) {
-    exit;
-}
-
-foreach (explode("\r\n", $headers) as $header) {
-    header($header);
-}
-
+$imageInfo = getimagesize($url);
+header('Content-type: '.$imageInfo['mime']);
 readfile($url);
 exit;