Card operations fail if in yubi mode, and non yubi reader is present.

```
% pkpass card
####################
Yubico YubiKey OTP+FIDO+CCID
Cherry GmbH SmartTerminal XX44
####################

Using SlotYubico YubiKey OTP+FIDO+CCID


PKPassError: Unsupported SC type for backend yubi.
Yubico not in:
Cherry GmbH SmartTerminal XX44
```