Fix new pycodestyle format error

dt3310321 · dt3310321 · commit 3c980ed12326 · 2019-03-01T18:11:06.000+08:00
diff --git a/qcloud_cos/cos_threadpool.py b/qcloud_cos/cos_threadpool.py
@@ -36,7 +36,7 @@ def run(self):
                 self._task_queue.task_done()
 
     def get_result(self):
-            return self._succ_task_num, self._fail_task_num, self._ret
+        return self._succ_task_num, self._fail_task_num, self._ret
 
 
 class SimpleThreadPool:
