database/sql: ensure correct mysql binding

In some packages, mysql is binded to 0.0.0.0 with is not good for
HAproxy.
We have to ensure that MySQL is binded to api_eth to avoid this issue.

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Merge pull request #572 from enovance/mysql-binding

database/sql: ensure correct mysql binding