Android only DEFLATED entries can have EXT descriptor

[gamebeaker]

reference: LagradOst/QuickNovel#312

This app uses https://github.com/psiegman/epublib/ as library.
As it looks inactive to me i am raising the issue here.

The addon WebToEpub changed the zip library used to create epubs and now this error happens.
Why do i think it isn't an error from WebToEpub?
The program epub-checker uses the official epubcheck library and doesn't show any zip errors.

That's why i think it isn't a WebToEpub issue (dteviot/WebToEpub#1887)

[jiakuan]

Will have a look when I have a chance.
In the meantime, any PRs are welcome.