libplugin: take into account --i-promise-to-fix-broken-api-user for output.

Somehow we missed this when we added libplugin support.

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

plugins/libplugin.c

@@ -235,8 +235,7 @@ bool command_deprecated_out_ok(struct command *cmd,
 	return deprecated_ok(command_deprecated_ok_flag(cmd),
 			     tal_fmt(tmpctx, "%s.%s", cmd->methodname, fieldname),
 			     depr_start, depr_end,
-			     /* FIXME: Get api begs from lightningd! */
-			     NULL,
+			     cmd->plugin->beglist,
 			     NULL, NULL);
 }