bug fix: when no or only one backend is defined, don't display list
bug fix: when no or only one backend is defined, don't display list

There is no need to activate/deactivate backends if there's no backend,
let's not confuse the users with an useless menu :)

opinkerfi/adagios,zengzhaozheng/adagios,opinkerfi/adagios,kb2ma/adagios,kaji-project/adagios,kaji-project/adagios,kb2ma/adagios,kb2ma/adagios,zengzhaozheng/adagios,kaji-project/adagios,zengzhaozheng/adagios,kaji-project/adagios,zengzhaozheng/adagios,opinkerfi/adagios,kb2ma/adagios,opinkerfi/adagios