daemon: fix BIP68 support.

We got the -> second translation wrong by a factor of 512, and also we
need to move the median time in our tests otherwise bitcoind won't let
us spend the tx.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

bitcoin/locktime.c

@@ -66,7 +66,7 @@ u32 rel_locktime_to_seconds(const struct rel_locktime *rel)
 {
 	assert(rel_locktime_is_seconds(rel));
 #if HAS_BIP68
-	return rel->locktime & BIP68_LOCKTIME_MASK;
+	return (rel->locktime & BIP68_LOCKTIME_MASK) << BIP68_SECONDS_SHIFT;
 #else
 	return rel->locktime - SECONDS_POINT;
 #endif

daemon/test/test.sh

@@ -224,8 +224,11 @@ if [ -n "$TIMEOUT_ANCHOR" ]; then
     TIME=$(($TIME + 24 * 60 * 60))
     lcli1 dev-mocktime $TIME
 
+    # Move bitcoind median time as well, so CSV moves.
+    $CLI setmocktime $TIME
+    $CLI generate 6
+    
     # Due to laziness, we trigger by block generation.
-    $CLI generate 1
     TIME=$(($TIME + 1))
     lcli1 dev-mocktime $TIME
     sleep 2