Fix GitLab Integration

Let’s say a developer wants to change the label from “in development” to “ready to ship”, he has to un-mark the “in development” label and only then mark the “ready to ship” label, instead of just changing it. If I’m rephrasing it – using only a single “:” makes the labels behave like “checkbox buttons”, when you actually want it to behave as a “radio buttons” (therefore this label should contain a double “::”, and to look like “Aha!::In development”).

For more details please see: https://gitlab.com/gitlab-org/gitlab/-/issues/9175