Fix incorrect transaction index in MEV Boost processing

Node/src/ethereum_l1/execution_layer.rs

@@ -276,7 +276,7 @@ impl ExecutionLayer {
         if send_to_contract {
             let pending = self.provider_ws.send_raw_transaction(&buf).await?;
 
-            tracing::debug!("Proposed new block, with hash {}", pending.tx_hash());
+            tracing::debug!("Send raw transaction, with hash {}", pending.tx_hash());
         }
 
         Ok(buf)

Node/src/mev_boost/constraints.rs

@@ -26,7 +26,7 @@ impl ConstraintsMessage {
             .iter()
             .map(|message| Constraint {
                 tx: message.clone(),
-                index: Some(0),
+                index: None,
             })
             .collect();
         Self {

Node/src/node/mod.rs

@@ -20,6 +20,7 @@ use operator::{Operator, Status as OperatorStatus};
 use preconfirmation_helper::PreconfirmationHelper;
 use preconfirmation_message::PreconfirmationMessage;
 use preconfirmation_proof::PreconfirmationProof;
+use tracing_subscriber::field::debug;
 use std::{
     collections::HashMap,
     sync::{
@@ -516,6 +517,7 @@ impl Node {
             )
             .await?;
 
+        debug!("Proposed new block, with hash {}", alloy::primitives::keccak256(&tx));
         // insert transaction
         self.preconfirmation_txs
             .lock()