refresh remote leaseset on udp ack timeout

libi2pd/Datagram.cpp

@@ -747,6 +747,15 @@ namespace datagram
 		if(ls && ls->GetExpirationTime() > oldExpire) m_RemoteLeaseSet = ls;
 	}
 
+	void DatagramSession::RequestUpdatedLeaseSet ()
+	{
+		if (!m_RequestingLS)
+		{
+			m_RequestingLS = true;
+			m_LocalDestination->RequestDestination(m_RemoteIdent, std::bind(&DatagramSession::HandleLeaseSetUpdated, this, std::placeholders::_1));
+		}
+	}
+
 	void DatagramSession::FlushSendQueue ()
 	{
 		if (m_SendQueue.empty ()) return;

libi2pd/Datagram.h

@@ -85,6 +85,8 @@ namespace datagram
 			void SetVersion (DatagramVersion version) { m_Version = version; }
 
 			void DropSharedRoutingPath () { if (m_RoutingSession) m_RoutingSession->SetSharedRoutingPath (nullptr); }
+			// request LeaseSet update from floodfill in case our copy contains dead leases
+			void RequestUpdatedLeaseSet ();
 
 		struct Info
 		{

libi2pd_client/UDPTunnel.cpp

@@ -216,6 +216,7 @@ namespace client
 						if (session)
 						{
 							session->DropSharedRoutingPath ();
+							session->RequestUpdatedLeaseSet (); // in case current leases are dead
 							m_Destination->SendDatagram (session, nullptr, 0, 0, 0, &options);
 						}
 					}