fixed possible crash at shutdown

libi2pd/Transports.cpp

@@ -55,6 +55,13 @@ namespace transport
 			m_Thread->join ();
 			m_Thread = nullptr;
 		}
+		if (!m_Queue.empty ())
+		{
+			// clean up queue
+			std::queue<std::shared_ptr<Keys> > tmp;
+	   		std::swap (m_Queue, tmp);
+		}
+		m_KeysPool.CleanUpMt ();
 	}
 
 	template<typename Keys>

libi2pd/Transports.h

@@ -54,8 +54,8 @@ namespace transport
 		private:
 
 			const int m_QueueSize;
-			std::queue<std::shared_ptr<Keys> > m_Queue;
 			i2p::util::MemoryPoolMt<Keys> m_KeysPool;
+			std::queue<std::shared_ptr<Keys> > m_Queue;
 
 			bool m_IsRunning;
 			std::unique_ptr<std::thread> m_Thread;