If worker group id is null,don't need to set the value of the worker group (#3460)

* [Fix-3423][dao][sql]Fixed that the resource file of the task node can't be found when upgrade from 1.2.0 to 1.3.x

* [Fix-3423][dao]If worker group id is null,don't need to set the value of the worker group

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

@@ -297,11 +297,14 @@ public abstract class UpgradeDao extends AbstractBaseDao {
                 for (int i = 0 ;i < tasks.size() ; i++){
                     JSONObject task = tasks.getJSONObject(i);
                     Integer workerGroupId = task.getInteger("workerGroupId");
-                    if (workerGroupId == null || workerGroupId == -1) {
-                        task.put("workerGroup", "default");
-                    }else {
-                        task.put("workerGroup", oldWorkerGroupMap.get(workerGroupId));
+                    if (workerGroupId != null) {
+                        if (workerGroupId == -1) {
+                            task.put("workerGroup", "default");
+                        } else {
+                            task.put("workerGroup", oldWorkerGroupMap.get(workerGroupId));
+                        }
                     }
+
                 }
 
                 jsonObject.remove(jsonObject.getString("tasks"));