fix deploy when bs=2 (PaddlePaddle#6915)

Author: jerrywgz

deploy/python/infer.py

@@ -154,7 +154,7 @@ def postprocess(self, inputs, result):
         np_boxes_num = result['boxes_num']
         if sum(np_boxes_num) <= 0:
             print('[WARNNING] No object detected.')
-            result = {'boxes': np.zeros([0, 6]), 'boxes_num': [0]}
+            result = {'boxes': np.zeros([0, 6]), 'boxes_num': np_boxes_num}
         result = {k: v for k, v in result.items() if v is not None}
         return result
 
@@ -402,10 +402,8 @@ def predict_image(self,
                         self.pred_config.labels,
                         output_dir=self.output_dir,
                         threshold=self.threshold)
-
             results.append(result)
             print('Test iter {}'.format(i))
-
         results = self.merge_batch_result(results)
         if save_results:
             Path(self.output_dir).mkdir(exist_ok=True)