Realtime for replays not working

Hi,

I was trying to set `coordinator->SetRealtime(true);` and then launching a replay. The replay loads but it gets stuck on the first game loop, or rather before that. `OnGameStart()` gets called and also ends. But `OnStep()` never gets called. When I pause the execution it seems that it waiting [here](https://github.com/Blizzard/s2client-api/blob/master/src/sc2api/sc2_connection.cc#L170).

Looking at issue #167 it seems that it already worked at one point.

Regards