Update requirements.txt

requirements.txt

@@ -12,7 +12,7 @@ PyYAML>=5.3.1
 requests>=2.23.0
 scipy>=1.4.1
 thop>=0.1.1  # FLOPs computation
-torch==2.1.0  # see https://pytorch.org/get-started/locally (recommended)
+torch==1.9.0  # see https://pytorch.org/get-started/locally (recommended)
 torchvision==1.1.0
 torchaudio==0.8.0
 tqdm>=4.64.0