hs: Don't BUG() when setting up RP congestion control
It is possible to not have the descriptor anymore by the time the rendezvous circuit opens. Don't BUG() on that.
Instead, when sending the INTRODUCE1 cell, make sure the descriptor we have (or have just fetched) matches what we setup in the rendezvous circuit.
If not, the circuit is closed and another one is opened for a retry.
Fixes #40576 (closed)
Signed-off-by: David Goulet dgoulet@torproject.org