[rbridge] Consensus Check: Decapsulation check optional

[Eastlake III Donald-LDE008]

This is a check via the mailing list to confirm or refute an apparent
consensus at the Philadelphia meeting:


******* Keep the reporting by RBridges in the link state database of
root bridge IDs observed mandatory, as in the current (-07) draft, but
make the "decapsulation" check optional.


If no particular controversy arises over this in the next two weeks,
We will declare it to be the working group consensus.

Thanks,
Donald & Erik