Disable pthread on Darwin-9.*-powerpc (Ruby bug #193)

[OBATA Akio <obache%NetBSD.org@localhost>]

Hi,

Now, pkgsrc disable pthread for ruby18-base on Darwin-9.*-powerpc
due to Ruby bug #193.
 http://redmine.ruby-lang.org/issues/show/193
It was added after updated to 1.8.3.22, but the bug report said
it was resolved in patch 22.

Is it still required on pkgsrc?

--
"Of course I love NetBSD":-)
OBATA Akio / obache%NetBSD.org@localhost