fix(network): fix heartbeat failure caused by inability to obtain peer address when receiving UDP data (#2364)

Fix #2363.

The root cause is that when starting onebox with `--use_product_config`, both replica
servers and meta servers use [src/server/config.ini](https://github.com/apache/incubator-pegasus/blob/a9a11da886bd32d170fc166c08b69210d89d6a52/src/server/config.ini)
instead of [src/server/config.min.ini](https://github.com/apache/incubator-pegasus/blob/a9a11da886bd32d170fc166c08b69210d89d6a52/src/server/config.min.ini).
As a result, beacons are sent and received over **UDP** instead of **TCP**.

The UDP implementation uses Boost.Asio APIs. If the sender socket does not call `connect()`,
then calling `remote_endpoint()` on the receiver socket will always fail.

The fix is to remove the logic that calls `remote_endpoint()` on the receiving side. This logic
was introduced in #1658 to handle cross-network
scenarios (when the address in the message header differs from the actual socket connection
address, the non-forwarding path corrects it to a recognizable address). Since UDP is primarily used
for the heartbeat scenario, and `beacon_msg` already contains `from_node` and `hp_from_node`,
this logic can be removed.

Author: empiredan

src/rpc/asio_net_provider.cpp

@@ -348,19 +348,6 @@ void asio_udp_provider::do_receive()
                 return;
             }
 
-            // Get the remote endpoint of the socket.
-            boost::system::error_code ec;
-            auto remote = _socket->remote_endpoint(ec);
-            if (ec) {
-                LOG_ERROR("failed to get the remote endpoint: {}", ec.message());
-                do_receive();
-                return;
-            }
-
-            auto ip = remote.address().to_v4().to_ulong();
-            auto port = remote.port();
-            const auto &remote_addr = ::dsn::rpc_address(ip, port);
-
             auto hdr_format = message_parser::get_header_type(_recv_reader._buffer.data());
             if (NET_HDR_INVALID == hdr_format) {
                 LOG_ERROR("{}: asio udp read failed: invalid header type '{}'",
@@ -384,23 +371,6 @@ void asio_udp_provider::do_receive()
                 return;
             }
 
-            if (msg->header->from_address != remote_addr) {
-                if (!msg->header->context.u.is_forwarded) {
-                    msg->header->from_address = remote_addr;
-                    LOG_DEBUG("{}: message's from_address {} is not equal to socket's remote_addr "
-                              "{}, assign it to remote_addr.",
-                              _address,
-                              msg->header->from_address,
-                              remote_addr);
-                } else {
-                    LOG_DEBUG("{}: message's from_address {} is not equal to socket's remote_addr "
-                              "{}, but it's forwarded message, ignore it!.",
-                              _address,
-                              msg->header->from_address,
-                              remote_addr);
-                }
-            }
-
             msg->to_address = _address;
             msg->to_host_port = _hp;
             if (msg->header->context.u.is_request) {