修复漏洞（对报错信息进行自定义，避免泄露系统敏感信息）

ruoyi-bussiness/src/main/java/com/ruoyi/cms/util/StringUtil.java

@@ -229,7 +229,7 @@ public class StringUtil {
      * @param request
      * @return
      */
-    private static String getProxyServer(HttpServletRequest request) {
+    public static String getProxyServer(HttpServletRequest request) {
         if (request == null) {
             return null;
         }