SPEC: Update spec file for krb5_local_auth_plugin
    
    krb5_localauth_plugin could be build only with MIT kerberos >= 1.12.
    However, this feature was backported in downstream to older version
    of kerberos. So there were packaging failures
    
    error: Installed (but unpackaged) file(s) found:
       /usr/lib/sssd/modules/sssd_krb5_localauth_plugin.so
    RPM build errors:
        Installed (but unpackaged) file(s) found:
       /usr/lib/sssd/modules/sssd_krb5_localauth_plugin.so
    Child returncode was: 1
    EXCEPTION: Command failed. See logs for output.
    
    Reviewed-by: Petr Cech <pcech@redhat.com>