bcli: don't log failed sendrawtransaction attempts twice

They are already logged both in bcli, and in lightningd.
This just adds a lot of noise to the logs. We keep successed attempts
though for the tests.

Signed-off-by: Antoine Poinsot <darosior@protonmail.com>

plugins/bcli.c

@@ -625,6 +625,8 @@ static struct command_result *process_sendrawtransaction(struct bitcoin_cli *bcl
 {
 	struct json_stream *response;
 
+	/* This is useful for functional tests. */
+	if (*bcli->exitstatus == 0)
 		plugin_log(bcli->cmd->plugin, LOG_DBG, "sendrawtx exit %i (%s)",
 			   *bcli->exitstatus, bcli_args(bcli));