Fix loss NaN bug when training HRSID dataset.

[zytx121]

Thanks for your contribution and we appreciate it a lot. The following instructions would make your pull request more healthy and more easily get feedback. If you do not understand some items, don't worry, just make the pull request and seek help from maintainers.

Motivation

close #759

Modification

Please briefly describe what modification is made in this PR.

BC-breaking (Optional)

Does the modification introduce changes that break the back-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. The documentation has been modified accordingly, like docstring or example tutorials.

[liuyanyi]

It seems 'FilterAnnotations' is under mmdet, should we add scope?

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (dev-1.x@53fc8b8). Click here to learn what that means.
Patch has no changes to coverable lines.

Additional details and impacted files

@@            Coverage Diff             @@
##             dev-1.x     #760   +/-   ##
==========================================
  Coverage           ?   79.35%           
==========================================
  Files              ?      100           
  Lines              ?     7267           
  Branches           ?     1039           
==========================================
  Hits               ?     5767           
  Misses             ?     1162           
  Partials           ?      338           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.