www/metacafe_dl: Unbreak fetch (sort of)
The previous commit removed the blanking of EXTRACT_SUFX and EXTRACT_ONLY
thinking that it was a mistake. The distfile actually has no extension,
so this is really needed. Without it, the checksum can't even start.
The MASTER_SITES is gone. The file is still fetchable because it is cached
but at some point it is going to disappear unless somebody preserves it.