Log Message:
asio: build fix for NetBSD > 9.99.14

Carry over the same patch from the Boost meta-pkg to fix this same
file in this version of the asio implementation. (The patch looks a
little ungainly in isolation, but is simpler than creating multiple
#if/#else blocks in the target file.)

(TBD: this package is likely redundant, as a newer version of it is
subsumed within the Boost libraries. The only package depending on it
is abiword-plugins. At first glance, it appears that abiword-plugins
could simply be patched to reference the Boost namespace for this
functionality. But I haven't confirmed if there are any specific
functional gaps between the two implementations, so I'm making this
quick build fix for now.)