- is_trampoline was True iff we are the final recipient of a trampoline payment
- in that case, we were only comparing htlc.cltv_expiry against the outer onion cltv
- we should and do now also compare against the inner onion cltv
- the checks are changed from "!=" to "<", to adapt to bolts PR 1032
- see b38156b951
- note that the leniency is needed for the cltv off-by-one
added in eca10eb04d to work