net-p2p/monero-cli: unbreak with boost 1.67

In file included from src/cryptonote_basic/hardfork.cpp:33:
In file included from src/blockchain_db/blockchain_db.h:42:
In file included from src/cryptonote_basic/hardfork.h:31:
contrib/epee/include/syncobj.h:37:10: fatal error: 'boost/thread/v2/thread.hpp' file not found
#include <boost/thread/v2/thread.hpp>

^~~~~~~~~~~~~~~~~~~~~~~~~~~~

In file included from src/rpc/daemon_handler.cpp:29:
In file included from src/rpc/daemon_handler.h:36:
In file included from src/p2p/net_node.h:41:
In file included from contrib/epee/include/net/levin_server_cp2.h:32:
In file included from contrib/epee/include/net/abstract_tcp_server2.h:324:
contrib/epee/include/net/abstract_tcp_server2.inl:44:10: fatal error: 'boost/thread/v2/thread.hpp' file not found
#include <boost/thread/v2/thread.hpp> // TODO

^~~~~~~~~~~~~~~~~~~~~~~~~~~~

PR: 227427
Reported by: antoine (via exp-run)