don't handle ack request for router

libi2pd/ECIESX25519AEADRatchetSession.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2021, The PurpleI2P Project
+* Copyright (c) 2013-2023, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -335,6 +335,7 @@ namespace garlic
 				case eECIESx25519BlkAckRequest:
 				{
 					LogPrint (eLogDebug, "Garlic: Ack request");
+					if (receiveTagset)
 						m_AckRequests.push_back ({receiveTagset->GetTagSetID (), index});
 					break;
 				}