fix response `content-type` is not set if access without access token

Kairlec

2023-05-15 ca103731c721aae3f5f622e58c679ed5c09fd9e9

 src/main/java/com/genersoft/iot/vmp/utils/DateUtil.java

@@ -45,7 +45,6 @@
   
   public static String ISO8601Toyyyy_MM_dd_HH_mm_ss(String formatTime) {
        return formatter.format(formatterCompatibleISO8601.parse(formatTime));

    }

    /**