fix: the ${name} is "" at [scripts/offline-installation-tool.sh]

Created by: daniel-hutao

I found the log: 【Save images: to ./kubesphere-images/.tar.gz <<<】when I use command "【./offline-installation-tool.sh -s -l images-list.txt -d ./kubesphere-images】 . So I look up the script: 【echo "Save images: "{name}" to "{ImagesDir}"/"{name}".tar.gz <<<"】，{name} is used before it's assigned.