udf: Remove web reference from UDF MAINTAINERS entry

Web link in UDF MAINTAINERS entry doesn't work and I don't use SF for UDF
development (and don't see a point to start using it). So just remove the link.
Reported-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJan Kara <jack@suse.cz>

MAINTAINERS

@@ -6572,7 +6572,6 @@ F:	drivers/net/ne-h8300.c
 
 UDF FILESYSTEM
 M:	Jan Kara <jack@suse.cz>
-W:	http://linux-udf.sourceforge.net
 S:	Maintained
 F:	Documentation/filesystems/udf.txt
 F:	fs/udf/