Fix group assigned to a ticket without right

[Lainow]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

Fixed an issue where a group could be added to a ticket even though it did not have the necessary permissions

Screenshots (if appropriate):

[jdurand-teclib]

LGTM once rector issue is fixed