reduce range for extra tags

libi2pd/ECIESX25519AEADRatchetSession.h

@@ -88,7 +88,8 @@ namespace garlic
 			bool IsNS () const { return m_IsNS; };
 			std::shared_ptr<ECIESX25519AEADRatchetSession> GetSession () { return m_Session; };
 			void SetTrimBehind (int index) { if (index > m_TrimBehindIndex) m_TrimBehindIndex = index; }; 
-
+			int GetTrimBehind () const { return m_TrimBehindIndex; };
+			
 			void Expire ();
 			bool IsExpired (uint64_t ts) const;			
 			

libi2pd/Garlic.cpp

@@ -553,7 +553,7 @@ namespace garlic
 					if (!session->HandleNextMessage (buf, length, nullptr, 0))
 					{
 						// try to gererate more tags for last tagset 
-						if (m_LastTagset && m_LastTagset->GetNextIndex () < 2*ECIESX25519_TAGSET_MAX_NUM_TAGS)
+						if (m_LastTagset && (m_LastTagset->GetNextIndex () - m_LastTagset->GetTrimBehind () < 3*ECIESX25519_MAX_NUM_GENERATED_TAGS))
 						{
 							auto maxTags = std::max (m_NumRatchetInboundTags, ECIESX25519_MAX_NUM_GENERATED_TAGS);
 							LogPrint (eLogWarning, "Garlic: trying to generate more ECIES-X25519-AEAD-Ratchet tags");