fix：Depend check bug (#2229)

* fix：#1787

* fix：#1787

dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/master/runner/MasterExecThread.java

@@ -674,9 +674,9 @@ public class MasterExecThread implements Runnable {
         TaskNode taskNode = dag.getNode(taskName);
         List<String> depNameList = taskNode.getDepList();
         for(String depsNode : depNameList ){
-
-            if(forbiddenTaskList.containsKey(depsNode) ||
-                    skipTaskNodeList.containsKey(depsNode)){
+            if(!dag.containsNode(depsNode)
+                    || forbiddenTaskList.containsKey(depsNode)
+                    || skipTaskNodeList.containsKey(depsNode)){
                 continue;
             }
             // dependencies must be fully completed