#1172 问题的解决 (#1173)

Co-authored-by: xiezhicheng <[email protected]>

Author: blanexie

webmagic-core/src/main/java/us/codecraft/webmagic/Spider.java

@@ -187,7 +187,7 @@ public Spider scheduler(Scheduler scheduler) {
      */
     public Spider setScheduler(Scheduler updateScheduler) {
         checkIfRunning();
-        SpiderScheduler oldScheduler = this.scheduler;
+        Scheduler oldScheduler = scheduler.getScheduler();
         scheduler.setScheduler(updateScheduler);
         if (oldScheduler != null) {
             Request request;