delete single message routing session immediately

Garlic.cpp

@@ -148,7 +148,7 @@ namespace garlic
 	size_t GarlicRoutingSession::CreateAESBlock (uint8_t * buf, const I2NPMessage * msg)
 	{
 		size_t blockSize = 0;
-		bool createNewTags = m_Owner && ((int)m_SessionTags.size () <= m_NumTags/2);
+		bool createNewTags = m_Owner && m_NumTags && ((int)m_SessionTags.size () <= m_NumTags/2);
 		UnconfirmedTags * newTags = createNewTags ? GenerateSessionTags () : nullptr;
 		*(uint16_t *)buf = newTags ? htobe16 (newTags->numTags) : 0; // tag count
 		blockSize += 2;
@@ -469,8 +469,16 @@ namespace garlic
 	I2NPMessage * GarlicDestination::WrapMessage (const i2p::data::RoutingDestination& destination, 
 		I2NPMessage * msg, bool attachLeaseSet)	
 	{
-		auto session = GetRoutingSession (destination, attachLeaseSet ? 32 : 0); // don't use tag if no LeaseSet
-		return session->WrapSingleMessage (msg);	
+		if (attachLeaseSet) // we should maintain this session
+		{	
+			auto session = GetRoutingSession (destination, 32);  // 32 tags by default
+			return session->WrapSingleMessage (msg);	
+		}
+		else // one time session
+		{
+			GarlicRoutingSession session (this, &destination, 0); // don't use tag if no LeaseSet
+			return session.WrapSingleMessage (msg);
+		}	
 	}
 
 	GarlicRoutingSession * GarlicDestination::GetRoutingSession (