When losing a locked vault attack, check if there is anything to lose before doing brush transfers

[0xSamWitch]

In LockedBankVaults.sol check if totalWon != 0 before trying all this.

    uint brushBurnt;
    if (!didAttackersWin) {
      // Lost so take a percentage from the loser's vaults
      uint amountToTreasure = totalWon / 2;
      uint amountToDao = totalWon / 4;
      brushBurnt = totalWon - (amountToTreasure + amountToDao);

      // Send to the treasure
      brush.transfer(pool, amountToTreasure);
      brush.transfer(dev, amountToDao);
      brush.burn(brushBurnt);
    }
    ```
Otherwise it can do 0 brush transfer which are not necessary, example:  https://ftmscan.com/tx/0xcdff939e3cac54bc7426ca8e62ea8398f03906fce09d62c56d80164d6b63b9bf