plugins/pay: use gossmods_from_listpeerchannels instead of private gossip_store records.

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

plugins/pay.c

@@ -1300,6 +1300,8 @@ static const char *notification_topics[] = {
 int main(int argc, char *argv[])
 {
 	setup_locale();
+	/* We are migrated, ready for public-only gossmap! */
+	gossmap_public_only = true;
 	plugin_main(argv, init, PLUGIN_RESTARTABLE, true, NULL, commands,
 		    ARRAY_SIZE(commands), NULL, 0, NULL, 0,
 		    notification_topics, ARRAY_SIZE(notification_topics),