Fix openutau crash when trying to install singer from an encrypted archive file

[oxygen-dioxide]

After this fix, openutau won't crash when trying to install singer from an encrypted archive file. It will show an error dialog.

Encrypted archive isn't supported because the password uses the local encoding of the creator's PC. The archive will be unable to extract by foreign users if the password contains non-ascii characters. We don't encourage the voicebank developers to distribute their voicebank in an encrypted archive file. related github issue: https://github.com/adamhathcock/sharpcompress/issues/536 related discussion: https://discord.com/channels/551606189386104834/801525671775043625/1162926497988882452