Bump rxjava from 3.0.11 to 3.0.12
Bump rxjava from 3.0.11 to 3.0.12

Bumps [rxjava](https://github.com/ReactiveX/RxJava) from 3.0.11 to 3.0.12.
- [Release notes](https://github.com/ReactiveX/RxJava/releases)
- [Commits](https://github.com/ReactiveX/RxJava/compare/v3.0.11...v3.0.12)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
tonivade/resp-server