Fix flakey email queue test

- Check for empty queue periodically, but timeout after 30 seconds
- Refactor test to use RSpec3 syntax

Signed-off-by: Zachary Auerbach <zak@zaksoup.com>
Fix TLDv1 typo to TLSv1

[#80756396]

Signed-off-by: Zachary Auerbach <zak@zaksoup.com>
Remove 'nil' default value for config_drive

Signed-off-by: Zachary Auerbach <zak@zaksoup.com>