travis: Bump ubuntu version to fix the glibc & glibcxx fault
travis: Bump ubuntu version to fix the glibc & glibcxx fault

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