[JIRA] (OVIRT-1609) Fix docker login to match all versions of docker

Fix docker login to match all versions of docker ------------------------------------------------ Key: OVIRT-1609 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-1609 Project: oVirt - virtualization made easy Issue Type: Improvement Reporter: Daniel Belenky Assignee: infra Docker login could fail on older versions if target repo was not specified