Scenario: A manifest starts out in live mode but then the recording is finalized and a subsequent update changes the state to a non-live manifest when the server has finished recording/transcoding/whatever with the full list of fragments. Without this patch, the manifest update task is never stopped on the live->non-live transition and will busy loop, burning through one CPU core. https://bugzilla.gnome.org/show_bug.cgi?id=786275