Fix regression in uncaughtException formatting.
Fix regression in uncaughtException formatting.

c424ceb3d introduced a regression in how we format uncaughtExceptions.
The wrong value was being passed to the logger.

Collinslenjo/ava,Collinslenjo/ava,BarryThePenguin/ava,sindresorhus/ava,andywer/ava-ts,avajs/ava,andywer/ava-ts,avajs/ava