Fix: cant change role using upper print role dropdown

[dinhtungdu]

Description of the Change

Fixes #57

Use different name allows user to use both upper and lower print role dropdown.

Alternate Designs

N/A.

Benefits

See above.

Possible Drawbacks

None identified.

Verification Process

1. Go to Users.
2. Select some users who have print role set.
3. Choose a role from the upper print role dropdown.
4. Click Change.
5. See the user's role is updated correctly.
6. Repeat the steps above but with the lower print role dropdown and see the same result.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.