e53674e py3: ipa_otptoken_import: fix calling unicode on bytes

Authored and Committed by mbasti 6 years ago
    py3: ipa_otptoken_import: fix calling unicode on bytes
    
    .decode() must be used instead
    
    https://pagure.io/freeipa/issue/4985
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>