Display (in logs) what was last received.

This lets us at least log the timeout message.
(We also get the last prompt as well.)

session.cpp

@@ -410,6 +410,10 @@ void Session::server_read(void) {
 
           server_read();
         } else {
+          if (!server_prompt.empty()) {
+            BUGZ_LOG(info) << "2C: [" << server_prompt << "]";
+            server_prompt.clear();
+          }
           BUGZ_LOG(warning) << "S: read_failed: socket.shutdown()";
           connected = false;
           socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both);
@@ -447,7 +451,6 @@ void Session::client_input(const std::string &input) {
   std::string temp = repr(input);
   BUGZ_LOG(info) << "CI: [" << temp << "]";
   director.client_input(input);
-
 }
 
 void Session::client_read(void) {