peer attach 'responses' mishandled if a sender and a receiver link are opened 'in parallel' with same name

If a sender link and a receiver link are both opened with the same name 'in parallel', i.e both are locally open but not yet remotely, the peers 'response' attaches will fail to be handled properly, with the link state not being updated correctly. Opening them sequentially, i.e awaiting the remote attach for the first link, then opening the second, is not affected.