Bugfix: use fuel public endpoint rather than internal one

Bugfix: use fuel public endpoint rather than internal one

1. The internal endpoint url of fuel is http.
2. Dovetail won't pass cacert to functest and yardstick containers if it's http.
3. For functest and rally, even if it uses internal url in the openrc file,
   they will still use public one somewhere.
4. Use fuel public endpoint which is https, so all containers will work with
   the cacert.

Change-Id: I3326c8d66bcad44ea81169ce0938cb0e247f498c
Signed-off-by: xudan <xudan16@huawei.com>