修复了没有检测到目标时出现error的问题

[nightwindnohen]

 in glee
    pred_masks = F.interpolate(mask_pred[None,], size=(padding_size[0], padding_size[1]), mode="bilinear",
  File "/home/user/.local/lib/python3.10/site-packages/torch/nn/functional.py", line 4020, in interpolate
    return torch._C._nn.upsample_bilinear2d(input, output_size, align_corners, scale_factors)
RuntimeError: Non-empty 4D data tensor expected but got a tensor with sizes [1, 0, 270, 480]```