Although I am not a loan officer, FHA does have certain guidelines regarding appliances (hot water heaters, ovens, etc). I would ask your agent to request from the seller that the oven be replaced.
It has been in my experience that if a property has something advertised in the multi listing service that is subsequently stolen that it should be replaced. It will depend on the appraiser & underwriter with your loan company if they will accept escrowed funds for a replacement or if an actual stove will have to be present.
Best of luck!
PS: If you don't have any luck getting the seller to replace the oven you may be able to find a gently used one at a Habitat for Humanity "Project Re-Store" location.