remove the absolute path to mysql sock and rely on the default system on...

| Q                    | A
| -------------------- | ---
| Bug fix?             | No
| New feature?         | No
| BC breaks?           | No
| CI currently passes? | ?
| Tests pass?          | Yes
| Scenarios pass?      | ?
| Checkstyle issues?*  | No
| PMD issues?**        | No
| Changelog updated?   | Yes
| Fixed tickets        | No
| Doc PR               | 
should be database_unix_socket: ~