refactor code style

dolphinscheduler-dao/src/main/java/org/apache/dolphinscheduler/dao/upgrade/ResourceDao.java

@@ -18,6 +18,7 @@
 package org.apache.dolphinscheduler.dao.upgrade;
 
 import org.apache.dolphinscheduler.common.utils.ConnectionUtils;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -35,6 +36,7 @@ public class ResourceDao {
 
     /**
      * list all resources
+     *
      * @param conn connection
      * @return map that key is full_name and value is id
      */