This setting was removed a long time ago, likely by "happy mistake" in a larger refactoring.
When enabled, players are granted any collected experience during the arena session as a reward when they die or reach the final wave of the arena. Note that deliberately leaving the arena is not included here, because "leaving" an arena is a highly ambiguous and conditional concept at the time of this commit. Figuring out when and how the experience reward should be added is complicated, and unless someone puts in a request for it, I think it's enough that the "legitimate" reasons for getting the experience (honorable death and reaching the final wave) are covered.
Closes#485
Andreas Troelsen
220197b5db