PeerStata.java: Remove dead code from acked()

[jogger]

Both acked() functions have this:

                } else if (state.getPushCount() <= 0) {

That code can never strike as we push() everything we pull off _outboundQueue. Thus the functions could be much shorter and more readable.

Also the comment there is misleading like at other places as well, because there is no order in _outboundMessages since #2293. Send order is guaranteed via _outboundQueue. #2293 made code a little bit faster, but improvements of traffic metrics claimed there are near to ridiculous.