adding reviewers group conflicts with allowed groups

The feature to add group of users as reviewers to CRUC-474 seems to be conflicting when the project has allowed users/groups restriction.

Basically with no users/groups restriction user can filter users/groups by its name prefix in the Edit Review dialog and pick up individual users or groups to be added to the review. This works as expected.

But if the project has restriction of users/groups allowed, it behaves wrongly.
1. if users with given prefix are found as allowed reviewers (either allowed users or members of allowed groups), only those users are listed in the Reviewers input. This seems fine
2. but if such users are found, the Reviewers input shows all group and users with the given prefix, regardless whether they are allowed as reviewers or not on this project. It is most likely possible to add those users as reviewers to review, regardless of the allowed reviewers restrictions.