Remove Enemy Cait's Headshot Call Out

Already posted this as a comment here:

http://boards.na.leagueoflegends.com/en/c/GD/2h4hoM6y-boom-headshot

Just saying it again here for good measure.

Enemy Caitlyn's "boom headshot" call out in-game is annoying as all hell. Please remove it, Riot. We all know what she's about to do. No need for her to say it every few seconds.