Fix deployment of Samba AD DC with MIT Kerberos
    
    When DES encryption is not supported in MIT Kerberos, deployment of
    Samba AD DC fails with
    
    "ERROR(ldb): uncaught exception - setup_kerberos_keys: generation of a
    des-cbc-md5 key failed: Bad encryption type"
    
    Fix it by not using DES encryption types in MIT build.
    
    Resolves #1757071