features: do not set option_support_large_channel in channel_announcement.

Spec is wrong (it says it should be compulsory), and Eclair doesn't set it
at all, leading to an error when they send their announcement_signatures.

Fixes: #3703
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-changed: large-channels: negotiate successfully with Eclair nodes.

common/features.c

@@ -61,10 +61,14 @@ static const struct feature_style feature_styles[] = {
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT,
 			  [BOLT11_FEATURE] = FEATURE_REPRESENT } },
+	/* FIXME: Spec is wrong, and Eclair doesn't include in channel_announce! */
+	/* BOLT #9:
+	 * | 18/19 | `option_support_large_channel` |... INC+ ...
+	 */
 	{ OPT_LARGE_CHANNELS,
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT,
-			  [CHANNEL_FEATURE] = FEATURE_REPRESENT_AS_OPTIONAL } },
+			  [CHANNEL_FEATURE] = FEATURE_DONT_REPRESENT } },
 #if EXPERIMENTAL_FEATURES
 	{ OPT_ONION_MESSAGES,
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,

tests/utils.py

@@ -46,8 +46,6 @@ def expected_channel_features(wumbo_channels=False, extra=[]):
     if EXPERIMENTAL_FEATURES:
         # OPT_ONION_MESSAGES
         features += [103]
-    if wumbo_channels:
-        features += [19]
     return hex_bits(features + extra)