Fix super-unlikely race introduced in 236618061a445d2cb11e72
Fix super-unlikely race introduced in 236618061a445d2cb11e72

Once the CNode has been added to vNodes, it is possible that it is
disconnected+deleted in the socket handler thread. However, after
that we now call InitializeNode, which accesses the pnode.

helgrind managed to tickle this case (somehow), but I suspect it
requires in immensely braindead scheduler.

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