update document

xxl-job-core/src/main/java/com/xxl/job/core/executor/XxlJobExecutor.java

             }
             jobThreadRepository.clear();
         }
-        if(jobHandlerRepository.size() >0 ){
-            for (Map.Entry<String, IJobHandler> item: jobHandlerRepository.entrySet()){
-                removeJobHandler(item.getKey(), "web container destroy and kill the jod handler");
-            }
-            jobHandlerRepository.clear();
-        }
+        jobHandlerRepository.clear();
 
 
         // destory JobLogFileCleanThread
         stopRpcProvider();
     }
 
-    private void removeJobHandler(String handlerId, String removeOldReason){
-        IJobHandler oldJobHandler = jobHandlerRepository.remove(handlerId);
-        if (oldJobHandler != null) {
-            oldJobHandler.destroy();
-        }
-    }
-
 
     // ---------------------- admin-client (rpc invoker) ----------------------
     private static List<AdminBiz> adminBizList;