`LiquidationOperations` loop should `break` on last Trove

[GalloDaSballo]

Impact

Apollon will not liquidate the last trove in batchLiquidateTroves However, the code is using a continue which means that the code will loop multiple times while performing no-ops

     if (troveManager.getTroveOwnersCount() <= 1) continue; // don't liquidate if last trove

Mitigation

Change the code to

      if (troveManager.getTroveOwnersCount() <= 1) break; // no more troves to liquidate

[sambP]