require 'org-install is obsolete since emacs 26.1

https://emacs.stackexchange.com/questions/42549/require-modename-vs-require-modename-install

https://github.com/emacs-china/Spacemacs-rocks#org-mode-%E7%AE%A1%E7%90%86-emacs-%E9%85%8D%E7%BD%AE