Remove unused import

Author: afilini

src/raw_client.rs

@@ -2,7 +2,7 @@
 //!
 //! This module contains the definition of the raw client that wraps the transport method
 
-use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque};
+use std::collections::{BTreeMap, BTreeSet, HashMap, VecDeque};
 use std::io::{BufRead, BufReader, Read, Write};
 use std::mem::drop;
 use std::net::{TcpStream, ToSocketAddrs};