Fixes scores not being reset in resetmatch warmup if sv_ready_restart_after_countdown is 1

This attempts to fix an issue where resetmatch is called when g_warmup is 1 and sv_ready_restart_after_countdown is 1. The scores do not get reset.

The solution seems to call Score_ClearAll() together with reset_map(). So far this works, but if they get called together all the time, I'd suggest putting Score_ClearAll() inside reset_map() would be cleaner.