Eeeek!
The consulate does NOT need to see a plane ticket for a spousal, or any other kind of visa. It's none of their business.
For visitors, an IO at an entry port may ask to see an onward ticket as evidence of intent to leave. But you are on a settlement track - you are coming here to join your husband and live here - you are one of us! So that rule doesn't apply. You can book your ONE-WAY ticket after they have issued your 2 year probationary visa.
If you have doubts, you can print this thread out and take it with you to show to them...