[Gameplay] Diana passive buff missing tooltip

I'd like to start this off by saying that this bug isn't game-breaking or really anything too serious at all. When you hover over the buff that Diana's passive gives, a box pops up that should tell you what the buff does. However, the text that should be there is missing, and instead is replaced with

Spell Not Found: game_buff_tooltip_DianaPassiveMarker

To recreate this, just auto attack with Diana in game and hover your mouse over the buff that appears above her spell bar.