[asio] example link dead

From: Stephan Menzel (stephan.menzel_at_[hidden])
Date: 2019-05-21 07:28:33

This is just a quick heads up.
The website link to a file example in asio:
https://www.boost.org/doc/libs/1_70_0/doc/html/boost_asio/example/cpp11/nonblocking/third_party_lib.cpp
... appears to be dead. 404.

HTH...
Stephan