meepctl fix when no config file present

//  operation == "" returns the whole group

func GetTargets(group string, operation string) []string {

	targets := []string{}

	if RepoCfg != nil {

		for target := range RepoCfg.GetStringMapString(group) {

			if RepoCfg.GetBool(group+"."+target+"."+operation) || operation == "" {

				targets = append(targets, target)

			}

		}

		sort.Strings(targets)

	}

	return targets

}