Clean up use to keep rust 1.43.0 from complaining (#9740)

ledger/src/blockstore_db.rs

@@ -1,7 +1,6 @@
 use crate::blockstore_meta;
 use bincode::{deserialize, serialize};
 use byteorder::{BigEndian, ByteOrder};
-use fs_extra;
 use log::*;
 pub use rocksdb::Direction as IteratorDirection;
 use rocksdb::{

ledger/src/snapshot_utils.rs

@@ -26,7 +26,6 @@ use std::{
 use tar::Archive;
 use tempfile::TempDir;
 use thiserror::Error;
-use zstd;
 
 pub const SNAPSHOT_STATUS_CACHE_FILE_NAME: &str = "status_cache";
 pub const TAR_SNAPSHOTS_DIR: &str = "snapshots";