Bump superdesk-core from 904da8b to 83a3cfa in /client

Bumps [superdesk-core](https://github.com/superdesk/superdesk-client-core) from `904da8b` to `83a3cfa`.
- [Release notes](https://github.com/superdesk/superdesk-client-core/releases)
- [Commits](superdesk/superdesk-client-core@904da8b...83a3cfa)

---
updated-dependencies:
- dependency-name: superdesk-core
  dependency-type: direct:production
...

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