message: Add DbgAssert for nBytesOrphanPool
diff: @@ -688,7 +688,7 @@ bool AddOrphanTx(const CTransaction &tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(c
  AssertLockHeld(cs_orphancache);
  if (mapOrphanTransactions.empty())
  - nBytesOrphanPool = 0;
  + DbgAssert(nBytesOrphanPool == 0, nBytesOrphanPool = 0);
  uint256 hash = tx.GetHash();
  if (mapOrphanTransactions.count(hash))
  