bolt04: Fix requirements of failure message for final node#1326

ekzyis wants to merge 3 commits intolightning:masterlightning/bolts:masterfrom

ekzyis:fix-1290-unclear-handling-of-invalid-onions-at-final-nodeekzyis/bolts:fix-1290-unclear-handling-of-invalid-onions-at-final-nodeCopy head branch name to clipboard