fix: code style (#1342)

config/env/watcher.go

@@ -20,10 +20,8 @@ func NewWatcher() (config.Watcher, error) {
 
 // Next will be blocked until the Stop method is called
 func (w *watcher) Next() ([]*config.KeyValue, error) {
-	select {
+	<-w.ctx.Done()
-	case <-w.ctx.Done():
 	return nil, w.ctx.Err()
-	}
 }
 
 func (w *watcher) Stop() error {