Fix receipt var read

Author: gabrielbosio

aggregator/internal/pkg/aggregator.go

@@ -278,7 +278,7 @@ func (agg *Aggregator) handleBlsAggServiceResponse(blsAggServiceResp blsagg.BlsA
 		"batchIdentifierHash", "0x"+hex.EncodeToString(batchIdentifierHash[:]))
 
 	for i := 0; i < MaxSentTxRetries; i++ {
-		_, err = agg.sendAggregatedResponse(batchData.BatchMerkleRoot, batchData.SenderAddress, nonSignerStakesAndSignature)
+		receipt, err := agg.sendAggregatedResponse(batchData.BatchMerkleRoot, batchData.SenderAddress, nonSignerStakesAndSignature)
 		if err == nil {
 			agg.logger.Info("Gas cost used to send aggregated response", "gasUsed", receipt.GasUsed)