message: Use emplace for inserting elements into the orphan pool
diff: @@ -40,10 +40,7 @@ bool CTxOrphanPool::AddOrphanTx(const CTransaction &tx, NodeId peer)
  }
  uint64_t txSize = RecursiveDynamicUsage(tx);
  - mapOrphanTransactions[hash].ptx = MakeTransactionRef(tx);
  - mapOrphanTransactions[hash].fromPeer = peer;
  - mapOrphanTransactions[hash].nEntryTime = GetTime();
  - mapOrphanTransactions[hash].nOrphanTxSize = txSize;
  + mapOrphanTransactions.emplace(hash, COrphanTx{MakeTransactionRef(tx), peer, GetTime(), txSize});
  for (const CTxIn &txin : tx.vin)
  mapOrphanTransactionsByPrev[txin.prevout.hash].insert(hash);
  