Wrong class number for LVIS 1.0 dataset

[cunjunyu]

Checklist

1. I have searched related issues but cannot get the expected help.
2. The bug has not been fixed in the latest version.

Describe the bug
Wrong class number for LVIS 1.0 dataset

Reproduction

1. What command or script did you run?
   N.A.
2. Did you make any modifications on the code or config? Did you understand what you have modified?
   Nope
3. What dataset did you use?
   LVIS1.0

Environment
N.A.

Error traceback
N.A.

Bug fix
For the config file for LVIS1.0 dataset, the class number should be 1203 instead of 1230 as indicated on the official website:
https://www.lvisdataset.org/dataset

mmdetection/configs/lvis/mask_rcnn_r50_fpn_sample1e-3_mstrain_1x_lvis_v1.py

Line 8 in 9596b9a

bbox_head=dict(num_classes=1230), mask_head=dict(num_classes=1230)))

[yhcao6]

It should be a typo, would you like to create a pr to fix that?