org-trello custom-set-variables时添加错误prefix

Spacemacs下,安装org-trello后会自动添加org-trello-current-prefix-keybinding的设置到dotspacemacs/emacs-custom-settings下,但是添加的却是有问题的设置

(custom-set-variables
 '(org-trello-current-prefix-keybinding "C-c o" nil (org-trello))
)

后面的"nil (org-trello)`是多余的。

感觉可能是spacemacs会自动把custom-set-variables的内容添加到dotspacemacs/emacs-custom-settings下,然后导致了这个问题。关键改对了之后,如果进custom-mode修改了其他variable/face的话,org-trello-current-prefix-keybinding又会被改成错误的版本。

org-trello里的code如下:

(custom-set-variables `(org-trello-current-prefix-keybinding
                        ,org-trello-default-prefix-keybinding))

求教如何修改才能使自动设置的custom variable为正确的值呢?