use NODEPOOL_RDO_PROXY in down_url in tripleo-quickstart release file

[chandan kumar]

We are testing IBM cloud and during repo setup,
https://logserver.rdoproject.org/35/44235/1/check/periodic-tripleo-ci-centos-9-containers-multinode-master-ibm/284f697/logs/undercloud/home/zuul/repo_setup.log
```
export NODEPOOL_RDO_PROXY=http://mirror.regionone.ibm-bm2-nodepool.rdoproject.org:8080/rdo
2022-07-27 07:25:50 | ++ NODEPOOL_RDO_PROXY=http://mirror.regionone.ibm-bm2-nodepool.rdoproject.org:8080/rdo

curl -Lvo /tmp/repo_role_tmp/delorean.repo https://trunk.rdoproject.org/centos9-master/tripleo-ci-testing/b9/79/b979b304ce5b7f7c85e20db171281a9f/delorean.repo
2022-07-27 07:25:50 | % Total % Received % Xferd Average Speed Time Time Time Current
2022-07-27 07:25:50 | Dload Upload Total Spent Left Speed
2022-07-27 07:26:05 |
  0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:01 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:02 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:03 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:04 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:05 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:06 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:07 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:08 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:09 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:10 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:11 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:12 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:13 --:--:-- 0
  0 0 0 0 0 0 0 0 --:--:-- 0:00:14 --:--:-- 0* Could not resolve host: trunk.rdoproject.org
2022-07-27 07:26:05 | * Closing connection 0
2022-07-27 07:26:05 | curl: (6) Could not resolve host: trunk.rdoproject.org
```

The reason it is coming
https://opendev.org/openstack/tripleo-quickstart/src/branch/master/config/release/tripleo-ci/CentOS-9/promotion-testing-hash-master.yml#L131
```
- type: file
    filename: delorean-master-deps.repo
    down_url: "https://trunk.rdoproject.org/{{ distro_ver }}-{{ release }}/delorean-deps.repo"
```
and
https://opendev.org/openstack/tripleo-quickstart/src/branch/master/roles/repo-setup/templates/repo_setup.sh.j2#L43
```
curl -Lvo /tmp/repo_role_tmp/{{ repo.filename }} {{ repo.down_url }}
```
repo.down_url = https://trunk.rdoproject.org/{{ distro_ver }}-{{ release }}/delorean-deps.repo

leading to above failure.
Overriding it to NODEPOOL_RDO_PROXY will fix the issue.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/tripleo-quickstart/+/851214

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/tripleo-quickstart/+/851214
Committed: https://opendev.org/openstack/tripleo-quickstart/commit/f50d529ccafd173bec580d806b171ffffacd564a
Submitter: "Zuul (22348)"
Branch: master

commit f50d529ccafd173bec580d806b171ffffacd564a
Author: Chandan Kumar (raukadah) <email address hidden>
Date: Wed Jul 27 17:31:51 2022 +0530

    Use nodepool_rdo_proxy url instead of rdo trunk url

    Currently in release file, we have rdo trunk url to lay
    down dlrn and dlrn-deps repo.

    In a restricted environment having network instability,
    curl fails with `could not connect to rdo trunk url error`
    while laying down the repo.

    RDO trunk contents are already mirrored on different
    cloud AFS mirror which are easily accessible.
    Let use that one and avoid these errors.

    This issue is seen in IBM cloud. Using nodepool_rdo_proxy
    url exists with in the cloud fixes the issue.

    Here is the testproject:
    https://review.rdoproject.org/r/c/testproject/+/44235/2#message-09494ed17f2f9404b1bac0166ce45514d7ba8d12

    Closes-Bug: #1982942

    Signed-off-by: Chandan Kumar (raukadah) <email address hidden>
    Change-Id: I06a1784931abb7eb1bab7fc9dcd8be2cc14cfb66