gwin32notificationbackend: Only warn once
Use a GOnce to make sure we only warn about notifications not being supported on Windows once, rather than on each attempted notification.
Signed-off-by: Philip Withnall withnall@endlessm.com
Helps: #1234
Use a GOnce to make sure we only warn about notifications not being supported on Windows once, rather than on each attempted notification.
Signed-off-by: Philip Withnall withnall@endlessm.com
Helps: #1234