MySQL: use same bootstrap script for both RH & Debian

It seems the bug* fixed upstream has been packaged uptsream for both Red
Hat and Debian/Ubuntu.

This patch aims to:
- move the debian script to one generic
- delete the red hat script
- use the generic for all OS.

* https://bugs.launchpad.net/codership-mysql/+bug/1087368

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>