fix bug

@@ -226,7 +226,7 @@ class Command(BaseCommand, LoggerMixin):
                                 '{0} [ocr_4 failed] [times={1}] [img_path={2}] [error={3}]'.format(
                                     self.log_base, times, img_path, traceback.format_exc()))
                         else:
-                            ocr_4_res = json.loads(ocr_4_response.json())
+                            ocr_4_res = ocr_4_response.json()
                             end_time = time.time()
                             speed_time = int(end_time - start_time)