This tiny PR cleans up the test feature_cltv.py in the following ways:
- fixes a typo (s/ctlv/cltv/); compared to CHECKLOCKTIMEVERIFY, CHECKTIMELOCKVERIFY probably also sounds good and you even get some search results for it, but it's still wrong ;)
- drops the unused "node" parameters from the tx modification functions
- don't return a copy from the tx modification functions; it's modified in-place, hence a copy is not needed and
cltv_validate(tx, ...)looks more natural thantx = cltv_validate(tx, ...)