Issues not sorted by Custom Field option sequence in issue nav

Reproduction Steps

1. Create a custom field that uses options - e.g. select list custom field
2. Add options to created custom field - "Really Bad", "Bad", "Awesome", "Trivial"
3. Create issues - one for each option
4. Search for issues in issue nav, and sort issues using the custom field created

What Happens
Issues are not sorted based on the sequence order which Custom Field options were defined in. Instead they are sorted alphabetically.

This is also reproducible with Radio Buttons custom fields