Bump mysql2 from 0.4.8 to 0.4.9
Bump mysql2 from 0.4.8 to 0.4.9

Bumps [mysql2](https://github.com/brianmario/mysql2) from 0.4.8 to 0.4.9.
- [Release notes](https://github.com/brianmario/mysql2/releases/tag/0.4.9)
- [Changelog](https://github.com/brianmario/mysql2/blob/master/CHANGELOG.md)
- [Commits](https://github.com/brianmario/mysql2/compare/0.4.8...0.4.9)
biow0lf/prometheus2.0,biow0lf/prometheus2.0,biow0lf/prometheus2.0,biow0lf/prometheus2.0