Fix problem with gitbook greater than 2.3.2

[mstn]

CLI version: 2.3.2
GitBook version: 3.2.3

Error: ENOENT: no such file or directory, open 'undefined/literature.bib'

Probably, it is due to plugin bibtex-citation

Note that if we downgrade gitbook, it works.

gitbook serve --gitbook=2.3.2

[yeyuguo]

you are right

[yeyuguo]

delete bibtex-citation