Bump superdesk-core from 6b75d6b to a19b3e1 in /client

Bumps [superdesk-core](https://github.com/superdesk/superdesk-client-core) from `6b75d6b` to `a19b3e1`.
- [Release notes](https://github.com/superdesk/superdesk-client-core/releases)
- [Commits](superdesk/superdesk-client-core@6b75d6b...a19b3e1)

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

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