Draft: Fix `Reviewers::Wanted` label when Reviewers list is empty (or reviewers are manually added).

This patch set just simple fix an issue when a MR does not have a Reviewers list for any reason (an uncovered subsystem maybe). If you add two reviewers by yourself, the label still persists there, unless all the Reviewers approve the MR.

The test case of this issue is pretty simple. All you need to do is get a MR with Reviewers::Wanted label set and change or the number of Reviewers list to meet the approval rules requirement or decrease the number of Reviewers for the MR. You won't see any change.

Signed-off-by: Julio Faracco jfaracco@redhat.com