Ticket #3637: hash_mismatch_on_rejoin_reproduce_r18742.7z

Identical simstate, but hash mismatch on rejoin. Replay file of host and rejoined client. Client (fatherbushido) rejoined turn 12(-1), "OOS" on turn 40. NOTICE: We had one rejoin before where no field was built and didn't get an OOS. In this replay there was only a field built. So perhaps sanderd17 is right.