Images that contain query string in path aren't embedded

If you have an image with src such as "/images/test.jpg?1234", it doesn't get embedded because file_exists fails on line 139 of mimemail.inc

I fixed that by adding this code before the file_exists line:

if (isset($file) && strpos($file, '?') > 0)
$file = substr($file, 0, strpos($file, '?'));