add try catch to MicroCore::get_tx

src/MicroCore.cpp

@@ -137,7 +137,15 @@ MicroCore::get_tx(const crypto::hash& tx_hash, transaction& tx)
     if (m_blockchain_storage.have_tx(tx_hash))
     {
         // get transaction with given hash
-        tx = m_blockchain_storage.get_db().get_tx(tx_hash);
+        try
+        {
+            tx = m_blockchain_storage.get_db().get_tx(tx_hash);
+        }
+        catch (TX_DNE const& e)
+        {
+            cerr << "MicroCore::get_tx: " << e.what() << endl;
+            return false;
+        }
     }
     else
     {