Fix heal_script for MySQL specifics

After running upgrade head->downgrade havana->upgrade head
on MySQL heal_script fails with several mistakes.

This change fix them. More details in related bug description.

Closes-bug: #1354218

Change-Id: I91cb21c4bc744f240bfb8bc6b2ed24b6e01f6095
Merge "Fix heal_script for MySQL specifics"