remove string_from_bytes import

src/service/sending/mod.rs

@@ -13,7 +13,7 @@ use std::{
 use crate::{
     api::{appservice_server, server_server},
     services,
-    utils::{calculate_hash, string_from_bytes},
+    utils::calculate_hash,
     Config, Error, PduEvent, Result,
 };
 use federation::transactions::send_transaction_message;