Update react/http requirement from ^0.7 to ^0.8
Update react/http requirement from ^0.7 to ^0.8

Updates the requirements on [react/http](https://github.com/reactphp/http) to permit the latest version.
- [Release notes](https://github.com/reactphp/http/releases)
- [Changelog](https://github.com/reactphp/http/blob/master/CHANGELOG.md)
- [Commits](https://github.com/reactphp/http/compare/v0.7.0...v0.8.4)
WildPHP/module-tgrelay