add retries to get hash url for images

[wes hayutin]

https://logs.rdoproject.org/19/587819/1/openstack-check/legacy-tripleo-ci-centos-7-ovb-3ctlr_1comp-featureset001-master/f832f68/job-output.txt.gz#_2018-08-01_14_12_29_451451

2018-08-01 14:12:29.451451 | tripleo-ovb-centos-7 | TASK [fetch-images : Get image expected checksum] ******************************
2018-08-01 14:12:29.464070 | tripleo-ovb-centos-7 | Wednesday 01 August 2018 14:12:29 +0000 (0:00:00.084) 0:19:01.222 ******
2018-08-01 14:12:33.223570 | tripleo-ovb-centos-7 | fatal: [undercloud]: FAILED! => {"changed": true, "cmd": ["curl", "-sfL", "http://images.rdoproject.org/master/rdo_trunk/959e1d7f755ee681b6f23b498d262a9e4dd6326f_4cbb1814/ironic-python-agent.tar.md5"], "delta": "0:00:03.077584", "end": "2018-08-01 14:12:33.202617", "msg": "non-zero return code", "rc": 7, "start": "2018-08-01 14:12:30.125033", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/587880

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/587880
Committed: https://git.openstack.org/cgit/openstack/tripleo-quickstart/commit/?id=fe44262554d8ad992505f91fcf30c9d734062dba
Submitter: Zuul
Branch: master

commit fe44262554d8ad992505f91fcf30c9d734062dba
Author: Wes Hayutin <email address hidden>
Date: Wed Aug 1 12:37:13 2018 -0400

    use retries when pulling image checksum

    I noticed that the image checksum failed in
    curl and we don't have any retries.

    Closes-Bug: #1784898
    Change-Id: I2ebc3d01679feb501b0391b2c5ef7198bf9f657b

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-quickstart 2.1.1 release.