additive ---> pre-additive

Thanks to luke
http://stacks.math.columbia.edu/tag/04VB#comment-1913

categories.tex

@@ -3608,7 +3608,7 @@ \section{Localization in categories}
 $S^{-1} \mathcal{C}$ (or, more precisely, its version for
 additive categories $\mathcal{C}$) actually generalizes the
 latter type of localization. Namely, a noncommutative ring can be
-viewed as an additive category with a single object (the morphisms
+viewed as a pre-additive category with a single object (the morphisms
 being the elements of the ring); a multiplicative subset of this
 ring then becomes a set $S$ of morphisms satisfying LMS1 (aka
 RMS1). Then, the conditions RMS2 and RMS3 for this category and