[FIX]repository config file generated always '0001-01-01T00:00:00Z'

Signed-off-by: Scaat Feng <scaat.feng@gmail.com>

pkg/repo/repo.go

@@ -112,6 +112,7 @@ func (r *File) Remove(name string) bool {
 
 // WriteFile writes a repositories file to the given path.
 func (r *File) WriteFile(path string, perm os.FileMode) error {
+	r.Generated = time.Now()
 	data, err := yaml.Marshal(r)
 	if err != nil {
 		return err