chore: bump assets from 764892a to 50f99d6 (hexojs#403)

Bumps [assets](https://github.com/hexojs/hexo-starter) from `764892a` to `50f99d6`.
- [Release notes](https://github.com/hexojs/hexo-starter/releases)
- [Commits](hexojs/hexo-starter@764892a...50f99d6)

---
updated-dependencies:
- dependency-name: assets
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>