Bump valid_email2 from 2.0.1 to 2.0.2 in /backend
Bump valid_email2 from 2.0.1 to 2.0.2 in /backend

Bumps [valid_email2](https://github.com/lisinge/valid_email2) from 2.0.1 to 2.0.2.
- [Changelog](https://github.com/lisinge/valid_email2/blob/master/CHANGELOG.md)
- [Commits](https://github.com/lisinge/valid_email2/compare/v2.0.1...v2.0.2)
roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen