UAID not always returned for subscription responses

[jrconlin]

Yes, this appears to be a very old bug.

There are at least two situations where the server may return a valid response that does not include the uaid field.

• If the subscription is for a channel that is already registered.
• if the subscription contains no channel ID (the server makes one up)

We should be consistent and ALWAYS return the UAID in our responses.