fix api header spec

pkg/es/api.go

@@ -223,7 +223,7 @@ func CallAPI(conf *cfg.Config, verb, path, data string) ([]byte, error) {
 		return nil, err
 	}
 
-	if !conf.HumanCat && strings.HasPrefix(path, "/_cat") {
+	if !conf.HumanCat || (conf.HumanCat && !strings.HasPrefix(path, "/_cat")) {
 		req.Header.Add("Content-Type", "application/json")
 		req.Header.Add("Accept", "application/json")
 	}