Fix ebnf terminals

[Zverik]

They didn't work before, and since a recent version of parser they produce exceptions.

[rezemika]

Thank you for your contribution! However, this repo is currently unmaintained (because the opening_hours field is so difficult to parse properly), so I probably won't merge it for now. I hope I'll be able to rewrite it cleanly one day...

[Zverik]

Thanks for the reply Michael! Yeah, I know it's on hold. But still, this is the best library for parsing the hours, and I'm using it in my mapping project. Let this PR sit here please, for somebody might encounter the same issue I did. I'm okay with not merging it.

[rezemika]

Oh thanks! So bad this field is so complicated, to write a simpler parser would mean giving up the parse of the most complex fields, so I don't know what to do... Does your version pass all the unit tests? If so I'm okay with merging it. :)

[Stemby]

This PR fixes issue #34.