Invalid default configuration

Running `engine_atecc/ecc-test-main` with a new chip, locks it with a bad configuration. The problem is that slot 1 is marked as [locked (0xFE)](https://github.com/AtmelCSO/cryptoauth-openssl-engine/blob/master/engine_atecc/cryptoauthlib/lib/tls/atcatls.c#L202) before the key is generated in `atcatls_config_default()`.
