why not invoke checkWorkerGroup in advance (#1747)

* issue https://github.com/apache/incubator-dolphinscheduler/issues/1743

* issue https://github.com/apache/incubator-dolphinscheduler/issues/1743

dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/worker/runner/FetchTaskThread.java

@@ -186,6 +186,10 @@ public class FetchTaskThread implements Runnable{
                         continue;
                     }
 
+                    if(!checkWorkerGroup(taskInstance, OSUtils.getHost())){
+                        continue;
+                    }
+
                     Tenant tenant = processDao.getTenantForProcess(taskInstance.getProcessInstance().getTenantId(),
                             taskInstance.getProcessDefine().getUserId());
 
@@ -203,11 +207,6 @@ public class FetchTaskThread implements Runnable{
 
                     logger.info("worker fetch taskId : {} from queue ", taskInstId);
 
-
-                    if(!checkWorkerGroup(taskInstance, OSUtils.getHost())){
-                        continue;
-                    }
-
                     // local execute path
                     String execLocalPath = getExecLocalPath();