Inference results appear weird when there is only one category in prototype

[YFZh]

I referred to that issue and made modifications to the code. I found that the prediction effect is not good, and the predicted box is often a box that is very close to the size of the image.

The following screenshot is my added code in detectron2/modeling/meta_arch/devit.py: @mlzxy

I hope to receive your help. Thanks.