Bump cornice from 3.4.2 to 3.4.3
Bump cornice from 3.4.2 to 3.4.3

Bumps [cornice](https://github.com/mozilla-services/cornice) from 3.4.2 to 3.4.3.
- [Release notes](https://github.com/mozilla-services/cornice/releases)
- [Changelog](https://github.com/Cornices/cornice/blob/master/CHANGES.txt)
- [Commits](https://github.com/mozilla-services/cornice/compare/3.4.2...3.4.3)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
Kinto/kinto-dist,Kinto/kinto-dist,mozilla-services/kinto-dist,mozilla-services/kinto-dist