message: Bump mempool counter on each successful IS lock
diff: @@ -805,6 +805,8 @@ void CInstantSendManager::UpdateWalletTransaction(const uint256& txid, const CTr
  if (tx) {
  GetMainSignals().NotifyTransactionLock(*tx);
  + // bump mempool counter to make sure newly mined txes are picked up by getblocktemplate
  + mempool.AddTransactionsUpdated(1);
  }
  }
  