Fix ledger distribution resync (#4013)

ledger/distribution/src/main.rs

@@ -15,8 +15,8 @@ use mc_ledger_db::{Ledger, LedgerDB};
 use mc_util_telemetry::{mark_span_as_active, start_block_span, tracer, Tracer};
 use protobuf::Message;
 use retry::{delay, retry, OperationResult};
-use rusoto_core::{Region, RusotoError};
-use rusoto_s3::{HeadObjectError, HeadObjectRequest, PutObjectRequest, S3Client, S3};
+use rusoto_core::{request::BufferedHttpResponse, Region, RusotoError};
+use rusoto_s3::{HeadObjectRequest, PutObjectRequest, S3Client, S3};
 use serde::{Deserialize, Serialize};
 use std::{fs, path::PathBuf};
 use tokio::runtime::Handle;
@@ -209,7 +209,11 @@ impl BlockHandler for S3BlockWriter {
                 let result = runtime.block_on(self.s3_client.head_object(req));
                 match result {
                     Ok(_) => OperationResult::Ok(true),
-                    Err(RusotoError::Service(HeadObjectError::NoSuchKey(_))) => {
+                    // Happens when the object doesn't exist, see
+                    // https://docs.aws.amazon.com/cli/latest/reference/s3api/head-object.html
+                    Err(RusotoError::Unknown(BufferedHttpResponse { status, .. }))
+                        if status.as_u16() == 404 =>
+                    {
                         OperationResult::Ok(false)
                     }
                     Err(e) => {