[Gameplay] Soraka Silence Bug

Currently Soraka's e is bugged and does not prevent untargetable champions from flashing out of the pool the moment they become targetable. It also seems to occasionally behave weirdly in other ways for champions that blink/teleport into pool.

Steps to reproduce:

1. Have an enemy champion with flash up use the active of Zhonya's Hourglass.
2. Wait until Zhonya's is almost finished and cast Soraka's e on top of the untargetable champion.
3. The enemy champion is not silenced and can immediately flash as soon as they become targetable again whether or not they are standing on the pool.