Remove reference to the removed parameter
Remove reference to the removed parameter

The records_use_fips parameter was removed when v1 API support was
removed[1]. This change removes remaining reference to the parameter
in README.

[1] fe68f0f1bc33ba99ea5612b4bf5877007bf7a5f7

Change-Id: Ica3cf7eba8a1e4ef87a832191b88fafd0afe02d4

openstack/designate-dashboard,openstack/designate-dashboard,openstack/designate-dashboard