When using -zip experiencing errors on a file from OPF Format Corpus about fido

[mistydemeo]

I see the cause of this one; I introduced this bug by accident.

The code here branches if the -zip option is selected:

if self.zip:
    self.identify_contents(filename, type=self.container_type(matches))

The type parameter is set to the type of the container, or None if the container type can't be detected by FIDO. Prior to 1b5698a, the only two values were zip and tar, but that added support for ole containers as well. FIDO uses this same method to determine container types for the purpose of identifying single files using container signatures, and for recursing into container files using -zip. It's the latter case that's breaking, since ole files are causing FIDO to try to unzip the files and identify the contents.

[mistydemeo]

Fixed by #73. I can confirm after that PR that -zip still works as expected on ZIP files, but no longer breaks on OLE files.

[sevein]

Thanks @mistydemeo! @jhsimpson is going to merge #73 soon.