This code will happily load a Disabled Queue and use it

If you've tried to go away from Constituency queues, you may have
disabled Queues.  If that Queue has an empty CorrespondAddress, you'll
get warnings before RTIR falls back to the Global settings.  If it has a
CorrespondAddress, RTIR will try to use that instead.
Merge branch '3.0/dont-use-disabled-queue' into 3.0-trunk