Title: #435: krb5: call krb5_auth_cache_creds() if a pssword is available
Thank you for the review. I removed the check from krb5_auth_cache_creds() and moved the
debug message to the error message of sss_authtok_get_password().
The 'Backend is marked offline, retry later!' messages is ok here because we just
want to return the offline state here. Always saying that delayed authentication which is
not enabled by default is not available might be irritating.
See the full comment at https://github.com/SSSD/sssd/pull/435#issuecomment-365901696