enable dead_code lint

src/database/key_value/users.rs

@@ -406,19 +406,6 @@ impl service::users::Data for KeyValueDatabase {
         Ok(())
     }
 
-    fn last_one_time_keys_update(&self, user_id: &UserId) -> Result<u64> {
-        self.userid_lastonetimekeyupdate.get(user_id.as_bytes())?.map_or(
-            Ok(0),
-            |bytes| {
-                utils::u64_from_bytes(&bytes).map_err(|_| {
-                    Error::bad_database(
-                        "Count in roomid_lastroomactiveupdate is invalid.",
-                    )
-                })
-            },
-        )
-    }
-
     fn take_one_time_key(
         &self,
         user_id: &UserId,