fix: 修复idea废弃api

Author: AutismSuperman

src/main/java/com/fulinlin/utils/VelocityTool.java

@@ -1,6 +1,7 @@
 package com.fulinlin.utils;
 
-import org.apache.commons.lang.StringUtils;
+
+import org.apache.commons.lang3.StringUtils;
 
 /**
  * @author fulin