Specific test for sysprefs.sql

Since bug 10610 has been pushed, the installer/data/mysql/sysprefs.sql
file is sorted by syspref names.

The failure is not a blocker one. The QAer is called to propose a
followup in order to fix the order rather than to fail QA the patch.

/!\ The file was generated using the mysql order by clause. Mysql sorts
underscore last.