Fix tls socket can block while doing clean shutdown on a forced disconnect

[arevetchi]

TLS socket can block on a force_disconnectwhen network interface is down, or the other end is not responding, as it calls clean_shutdown_and_close witch tries to shutdown tls socket gracefully.

This is a stack trace from one scenario when network is set down, or simply the cable gets pulled out for testing purposes, when pingreq timer fires it tries to to a clean tls socket shutdown and it block indefinitely.

#0  0x00007f26baafa21f in __GI___poll (fds=0x7f26b99f8180, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x000055b37e217265 in boost::asio::detail::socket_ops::poll_read (s=20, state=0 '\000', msec=-1, ec=...) at external/boost/libs/asio/include/boost/asio/detail/impl/socket_ops.ipp:2249
#2  0x000055b37e218349 in boost::asio::detail::socket_ops::sync_recv1 (s=20, state=18 '\022', data=0x7f26b012d800, size=17408, flags=0, ec=...) at external/boost/libs/asio/include/boost/asio/detail/impl/socket_ops.ipp:902
#3  0x000055b37df910d3 in boost::asio::detail::reactive_socket_service_base::receive<boost::asio::mutable_buffer> (this=0x7f26b0003a68, impl=..., buffers=..., flags=0, ec=...) at external/boost/libs/asio/include/boost/asio/detail/reactive_socket_service_base.hpp:366
#4  0x000055b37df90ff8 in boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>::read_some<boost::asio::mutable_buffer> (this=0x7f26b011f868, buffers=..., ec=...) at external/boost/libs/asio/include/boost/asio/basic_stream_socket.hpp:1035
#5  0x000055b37df91892 in boost::asio::ssl::detail::io<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor>, boost::asio::ssl::detail::shutdown_op> (next_layer=..., core=..., op=..., ec=...) at external/boost/libs/asio/include/boost/asio/ssl/detail/io.hpp:48
#6  0x000055b37df915d0 in boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor> >::shutdown (this=0x7f26b011f868, ec=...) at external/boost/libs/asio/include/boost/asio/ssl/stream.hpp:621
#7  0x000055b37df914dd in mqtt::tcp_endpoint<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor> >, boost::asio::strand<boost::asio::io_context::basic_executor_type<std::allocator<void>, 0ul> > >::shutdown_and_close_impl (this=0x7f26b011f860, s=..., ec=...) at external/mqtt_cpp/include/mqtt/tcp_endpoint.hpp:171
#8  0x000055b37df80ab4 in mqtt::tcp_endpoint<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::any_io_executor> >, boost::asio::strand<boost::asio::io_context::basic_executor_type<std::allocator<void>, 0ul> > >::clean_shutdown_and_close (this=0x7f26b011f860, ec=...) at external/mqtt_cpp/include/mqtt/tcp_endpoint.hpp:102
#9  0x000055b37deb27f1 in mqtt::endpoint<std::mutex, std::lock_guard, 2ul>::sync_shutdown (this=0x7f26b00020c0, s=...) at external/mqtt_cpp/include/mqtt/endpoint.hpp:5319
#10 0x000055b37deb2678 in mqtt::endpoint<std::mutex, std::lock_guard, 2ul>::force_disconnect (this=0x7f26b00020c0) at external/mqtt_cpp/include/mqtt/endpoint.hpp:1103
#11 0x000055b37deb25fd in mqtt::endpoint<std::mutex, std::lock_guard, 2ul>::set_pingresp_timer()::{lambda(boost::system::error_code)#1}::operator()(boost::system::error_code)::{lambda()#1}::operator()() const (this=0x7f26b00ad600) at external/mqtt_cpp/include/mqtt/endpoint.hpp:11552
...

[redboltz]

@arevetchi Thank you for sending the PR.
It seems that the first commit is essential. But CI reports some errors.
So I fix the CI issue with your commit as #1000,

[arevetchi]

@redboltz Thank you for prompt response