Actually pre-fill prefix in /prefix/add
Actually pre-fill prefix in /prefix/add

The previous code didn't create a Prefix object and instead passed a
string to the template that expected a Prefix object.

SpriteLink/NIPAP,garberg/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,garberg/NIPAP,garberg/NIPAP,garberg/NIPAP,garberg/NIPAP,SpriteLink/NIPAP,SpriteLink/NIPAP,SpriteLink/NIPAP,SpriteLink/NIPAP