Modules prompt triggers when empty module list is passed

[cjpearson]

When the modules flag is used for init, the prompt still shows if the list of modules is empty.

Current behavior

npx init => prompt shown ✅
npx init --modules '@nuxt/fonts' => no prompt ✅
npx init --modules => prompt shown ❌

Expected

npx init => prompt shown ✅
npx init --modules '@nuxt/fonts' => no prompt ✅
npx init --modules '' => no prompt ✅