Fixed prunable rollback deleting the rewards

If we rolled back to the last slot of an epoch (e.g. when loading a snapshot) on resuming from storage or starting warpsync we wrongly deleted the rewards

pkg/storage/prunable/prunable.go

@@ -194,9 +194,13 @@ func (p *Prunable) Rollback(targetEpoch iotago.EpochIndex, startPruneRange iotag
 		return ierrors.Wrapf(err, "failed to rollback decided upgrade signals epochs to target epoch %d", targetEpoch)
 	}
 
-	lastPrunedPoolRewardsEpoch, err := p.poolRewards.RollbackEpochs(targetEpoch)
-	if err != nil {
-		return ierrors.Wrapf(err, "failed to rollback pool rewards epochs to target epoch %d", targetEpoch)
+	var lastPrunedPoolRewardsEpoch iotago.EpochIndex
+	// Do not rollback the epoch if the targetSlot is the end of the epoch, because that is when we calculated the rewards.
+	if targetSlot := startPruneRange - 1; p.apiProvider.APIForSlot(targetSlot).TimeProvider().EpochEnd(targetEpoch) != targetSlot {
+		lastPrunedPoolRewardsEpoch, err = p.poolRewards.RollbackEpochs(targetEpoch)
+		if err != nil {
+			return ierrors.Wrapf(err, "failed to rollback pool rewards epochs to target epoch %d", targetEpoch)
+		}
 	}
 
 	for epochToPrune := targetEpoch + 1; epochToPrune <= max(