chore: make clippy happy

Author: zonyitoo

crates/shadowsocks-service/src/local/online_config/mod.rs

@@ -217,7 +217,7 @@ impl OnlineConfigService {
         // Check plugin whitelist
         if let Some(ref allowed_plugins) = self.allowed_plugins {
             for server in &online_config.server {
-                if let Some(ref plugin) = server.config.plugin() {
+                if let Some(plugin) = server.config.plugin() {
                     if !allowed_plugins.contains(&plugin.plugin) {
                         error!(
                             "server-loader task found not allowed plugin: {}, url: {}",