Bump brakeman from 4.0.0 to 4.0.1 in /backend
Bump brakeman from 4.0.0 to 4.0.1 in /backend

Bumps [brakeman](https://github.com/presidentbeef/brakeman) from 4.0.0 to 4.0.1.
- [Release notes](https://github.com/presidentbeef/brakeman/releases/tag/v4.0.1)
- [Changelog](https://github.com/presidentbeef/brakeman/blob/master/CHANGES)
- [Commits](https://github.com/presidentbeef/brakeman/compare/v4.0.0...v4.0.1)
roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen