net-p2p/libtorrent-rasterbar: unbreak with boost 1.69

In file included from include/libtorrent/chained_buffer.hpp:37:
include/libtorrent/disk_io_job.hpp:78:12: error: expected class name

, boost::noncopyable
         ^

In file included from src/http_stream.cpp:33:
In file included from include/libtorrent/http_stream.hpp:44:
include/libtorrent/proxy_base.hpp:49:20: error: unknown class name 'noncopyable'; did you mean 'boost::asio::noncopyable'?
class proxy_base : boost::noncopyable

^~~~~~~~~~~~~~~~~~
boost::asio::noncopyable

/usr/local/include/boost/asio/detail/noncopyable.hpp:38:28: note: 'boost::asio::noncopyable' declared here
using boost::asio::detail::noncopyable;

^

In file included from src/session.cpp:58:
include/libtorrent/tracker_manager.hpp:274:5: error: unknown class name 'noncopyable'; did you mean 'boost::asio::noncopyable'?

, boost::noncopyable
  ^~~~~~~~~~~~~~~~~~
  boost::asio::noncopyable

/usr/local/include/boost/asio/detail/noncopyable.hpp:38:28: note: 'boost::asio::noncopyable' declared here
using boost::asio::detail::noncopyable;

^

In file included from src/session.cpp:58:
include/libtorrent/tracker_manager.hpp:363:5: error: unknown class name 'noncopyable'; did you mean 'boost::asio::noncopyable'?

, boost::noncopyable
  ^~~~~~~~~~~~~~~~~~
  boost::asio::noncopyable

/usr/local/include/boost/asio/detail/noncopyable.hpp:38:28: note: 'boost::asio::noncopyable' declared here
using boost::asio::detail::noncopyable;

^

src/kademlia/dht_storage.cpp:186:74: error: unknown class name 'noncopyable'; did you mean 'boost::asio::noncopyable'?

class dht_default_storage TORRENT_FINAL : public dht_storage_interface, boost::noncopyable
                                                                        ^~~~~~~~~~~~~~~~~~
                                                                        boost::asio::noncopyable

/usr/local/include/boost/asio/detail/noncopyable.hpp:38:28: note: 'boost::asio::noncopyable' declared here
using boost::asio::detail::noncopyable;

^

In file included from include/libtorrent/kademlia/rpc_manager.hpp:56:
include/libtorrent/kademlia/observer.hpp:60:40: error: unknown class name 'noncopyable'; did you mean 'boost::asio::noncopyable'?
struct TORRENT_EXTRA_EXPORT observer : boost::noncopyable

^~~~~~~~~~~~~~~~~~
boost::asio::noncopyable

/usr/local/include/boost/asio/detail/noncopyable.hpp:38:28: note: 'boost::asio::noncopyable' declared here
using boost::asio::detail::noncopyable;

^

PR: 232525