Make enemies targetable in the last half second of Poppy's ult.

I think this would be a really good QOL improvement to Poppy, who already is a bit on the weak side of balance. This change would make it easier to chain CC with the instant cast of the ult. I've had a game, where I ulted a Renekton to line up the wall stun and finish him off under his turret, but as he landed he could activate his stun move and hit me with it through my E and wallstun making both of us standing awkwardly next to the wall and me getting killed. I don't know how much better could I have chained my E with the ult, as I was already spamming it at 800 APM waiting for him to land.