Add explicit license to FindLibuv.cmake
Add explicit license to FindLibuv.cmake

Was written by @joerg-krause who said it can be licensed the same as the rest.
https://github.com/luvit/luv/commit/b9012465944178a58fd32d8a90630c0fa97ca54e#commitcomment-18390894
zhaozg/luv,joerg-krause/luv,zhaozg/luv,joerg-krause/luv,luvit/luv,luvit/luv