Waiting until lightningd is up is too long: do a --version test in setup,
and then check that all reported versions match later on.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Segwit was merged, but the strings changed between there and segwit4
(also, my BIP9 patch changed the output).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>