fix(bridge-withdrawer, cli): use leading channel #6828

Job	Run time
run_checker / changes	4s
solidity-contracts-compiled	1m 9s
compiles	1m 30s
protos-compiled	31s
lockfile	21s
audit	0s
clippy	54s
custom-lints	2m 59s
doctest	1m 24s
rust	2m 20s
rust-ethereum	1m 28s
test / success	1s
	12m 41s

Provide feedback