Doesn't work with secrets that have no attachment

[cryonautlex]

If I have a REST Endpoint Key in Secret Server with no Attachment, I cannot fetch its Key Password label. I get this error instead:

C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzibar.rb:97:in` `
download_secret_file': There was an error getting the Key Password for secret 1
9730: File attachment not found. (RuntimeError)
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:129:in `download_one_secret'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:116:in `block in download_remote_secrets'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:114:in `each'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:114:in `download_remote_secrets'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:52:in `run!'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/actions/bundle.rb:45:in `run'
        from C:/tools/ruby23/lib/ruby/gems/2.3.0/gems/zanzibar-0.2.0/lib/zanzib
ar/cli.rb:136:in `bundle!'