Fix unsynchronized shared memory access

I had issues with the daemon hanging after the exit command, and this
seems like the culprit.

contrib/epee/include/console_handler.h

@@ -290,7 +290,7 @@ namespace epee
 
   private:
     async_stdin_reader m_stdin_reader;
-    bool m_running = true;
+    std::atomic<bool> m_running = {true};
   };