If a connection update (from central) overlaps a peripheral initiated
conneection param request, then central rejects peripheral request
and continues central procedure. This lead to an assert in peripheral
On instant there would not be an rx_node for notification, as this
would have been discarded by the reception of the REJECT.
This fix ensures that once an rx_node has been 'accepted' for retention
it will not be discarded/overwritten by future rx_nodes
The test will trigger the assert without the fix in.
Signed-off-by: Erik Brockhoff <erbr@oticon.com>
670bd3bed2