Update coinex_swap_rest.rs

exchanges/src/coinex_swap_rest.rs

@@ -6,7 +6,7 @@ use hex;
 use reqwest::Client;
 use rust_decimal::Decimal;
 use rust_decimal_macros::dec;
-use serde_json::{json, Value};
+use serde_json::Value;
 use crate::http_tool::RestTool;
 use crate::response_base::ResponseData;
 use sha2::{Digest, Sha256};