Description:
------------
When I use function mime_content_type to detect file types,
under windows, for a gif file, it always return "text/plain" for it,
even if mime_magic.debug is set to "on",

php under linux not tested.

Please fix it.

Thank u.

Reproduce code:
---------------
<?
echo mime_content_type('1.gif');
?> 

Expected result:
----------------
image/gif

Actual result:
--------------
text/plain