[fix] message: remove unused import

lib/core/message/responses.rs

@@ -24,7 +24,6 @@ use duniter_module::ModuleReqId;
 use duniter_network::requests::NetworkResponse;
 use dup_crypto::hashs::Hash;
 use dup_crypto::keys::*;
-use durs_blockchain_dal::entities::identity::DALIdentity;
 use std::collections::HashMap;
 
 /// Durs request response message