This is answer to your question:
What’s new in 6.33.5 (2015-Dec-28 09:13):
*) wireless - regular “wireless” package is now retired and replaced by “wireless-fp” and “wireless-cm2”;
This means that in update you are trying to do is the old wireless package missing - intentionally.
Therefore upload wireless-cm2 package to your router, activate it instead of old wireless package and everything should be fine for update after that.