thttpd: Fix SHA256 of the upstream tarball.

It's a bit unfortunate to see this, but while looking online to download
the old version of the file I found that MacPorts and FreeBSD had the
same issue:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199562

I've checked the diff as well and found no big functional changes,
except a function rename, copyright updates and changed syslog
priorities:

https://bz-attachments.freebsd.org/attachment.cgi?id=155775



Signed-off-by: aszlig <aszlig@redmoonstudios.org>