[Ballista] AoE spells proc on players with preparation status

[Liquefier]

Checklist

• [x ] I have searched for existing issues for issues like this one. The issue has not been posted. (Duplicate reports slow down development.)
• [x ] I have provided reproducable steps. (No "as the title says" posts please. Provide reproducable steps even if it seems like a waste of time.)
• [ ] I have provided my client version in the details. (type /ver into your game window)

Details

Upon raising from KO in ballista you are properly un-targetable, however spells such as diaga cast on a teammate in close proximity will still hit you before your preperations effect wears off

[ThoseWhoFight]

tested during test match today, that this is still an issue, very easily reproducible