Error when exporting empty result

[lethunder]

When you are on an index and you search for something that returns an empty table. When you try to export that it raises an error
uninitialized constant Class::ATTRIBUTE_TYPES

Export link you appear only if records > to 0

[andreibondarev]

@lethunder Thank you for flagging it. I'm not sure I have time to look into this error but if you're able to issue a PR with a fix -- I'll review it and merge it.

[darkaico]

@lethunder I was trying to reproduce it, but I could not. If I have an empty table, because of a search that throws that, or because I have no elements, Im still able to export without errors (and having an empty CSV of course, only headers)

Could you let me know if you're still having this error?