Wavebird receiver locks out if OLD_MODE polling is disabled

[ThadHouse]

I think I found at least what the wavebird receiver issue is caused by. I was noticing that the controller request was working, as long as the controller itself was turned off. However, as soon as I turned on the controller and moved an input, the data signal would actually latch high, and would not release this hold unless I removed power from the receiver. If I added back in the OLDMODE define in sync.h, this behavior didn't occur anymore, and the controller would fully enable. I wonder if the wavebird receiver just doesn't like getting interrupted during transmission, even accidentally, and just dies.

One thing is my wavebird is the original 900MHz version and not the 2.4 GHz version, so I wonder if the older versions behave differently on an interrupted transmission.

[ThadHouse]

Found out that reverting 6e869e2 fixes the issue, and allows my wavebird to work again. Was that commit needed for any specific reason? It seems like the wavebird just does not like getting polled too fast.