error Call-time pass-by-reference has been removed

PHP Fatal error: Call-time pass-by-reference has been removed in /var/www/rovira/data/www/rovira.by/core/cache/includes/elements/modsnippet/63.include.cache.php on line 3

<?php
$content = $modx->resource->content;
if(preg_match("/src=\"(.*?)\"/",$content,&$matches)){
$img = substr($matches[1],1,strlen($matches[1]));
}
else {
$img = «manager/templates/Rovira/img/logo.png»;
}
return $img;
return;