chore: bump assets from 764892a to 50f99d6

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] <[email protected]>

Author: dependabot[bot]