Fix MIT license link
Fix MIT license link

A trailing `/` is added to the URL otherwise Doxygen tries to resolve it
as a local reference and fails.

Rinnegatamante/vita-headers,vitasdk/vita-headers,vitasdk/vita-headers,vitasdk/vita-headers,Rinnegatamante/vita-headers,Rinnegatamante/vita-headers,vitasdk/vita-headers,Rinnegatamante/vita-headers