Don't proxy local files

classes/imagetools.class.php

       }
     }
 
-    if (preg_match('/^https:\/\/('.SITE_DOMAIN.'|'.IMAGE_DOMAIN.')\//', $Url)) {
+    if (preg_match('/^https:\/\/('.SITE_DOMAIN.'|'.IMAGE_DOMAIN.')\//', $Url) || $Url[0]=='/') {
       return $Url;
     } else {
       return 'https://'.IMAGE_DOMAIN.'?h='.rawurlencode(base64_encode(hash_hmac('sha256', $Url, IMAGE_PSK, true))).'&i='.urlencode($Url);