If you have a rental property that is vacant, then you simply have no rental activity for those years. The hobby rule is concerning earned income, not passive income which is how a rental activity is usually classified.
However, keep in mind that renovations and other expenses related to the property may not be deductible if the property was taken off the rental market. The key for deductions is that the property is rented out or actively trying to rent. And during the vacancy period, you will not be allowed to deduct the loss.
