fix: compile warnings after refactoring

src/http_server.rs

-use futures::future::{join_all, try_join_all};
-use futures::FutureExt;
+use futures::future::join_all;
 use serde::{Deserialize, Serialize};
 use std::{collections::HashMap, error::Error};
 

src/pico_service.rs

-pub use crate::schema::PICO_SERVICE_USER_NAME;
 use crate::tlog;
 use crate::traft::error::Error;
 use crate::unwrap_ok_or;