User role error on save settings

[pedro-mendonca]

Describe the bug Saving the settings is currently giving an error because it's pushing a key to an unexistent user roles array.

To Reproduce Steps to reproduce the behavior:

1. Go to Settings
2. Select whatever user roles you want
3. Save
4. See error

Expected behavior Reloading to the current Settings page, with the user roles as set in the previous save.

System (please complete the following information):

• Develpment branch