Saveload: Don't apply state ticks offset on load if not stored in save

src/saveload/afterload.cpp

@@ -872,7 +872,8 @@ bool AfterLoadGame()
 	if (SlXvIsFeaturePresent(XSLFI_VARIABLE_DAY_LENGTH, 1, 3)) {
 		/* CalTime is used here because EconTime hasn't been set yet, but this needs to be done before setting EconTime::Detail::SetDate,
 		 * because that calls RecalculateStateTicksOffset which overwrites DateDetail::_state_ticks_offset which is an input here */
-		_state_ticks = GetStateTicksFromDateWithoutOffset(CalTime::CurDate().base(), CalTime::CurDateFract()) + DateDetail::_state_ticks_offset;
+		_state_ticks = GetStateTicksFromDateWithoutOffset(CalTime::CurDate().base(), CalTime::CurDateFract());
+		if (SlXvIsFeaturePresent(XSLFI_VARIABLE_DAY_LENGTH, 3, 3)) _state_ticks += DateDetail::_state_ticks_offset;
 	}
 
 	/* Update current year