Ignore unknown Category instead of returning an error

[shamilsan]

I encountered a problem when trying to open one MSI package with undocumented “Number” category. In my opinion, it is better to ignore unknown categories rather than to return an error.

[shamilsan]

Dear @mdsteele,

What do you think about it?

[mdsteele]

Seems reasonable, sorry for the slow reply. Looks like there were some clippy errors unrelated to your change; if you rebase those should be fixed now, and then we can merge.

[shamilsan]

@mdsteele,

Thanks for your reply. I've synced my fork with the upstream, could you please try again?

[mdsteele]

Merged, thanks!