Dockerfiles: correct ENV format
Avoid docker warning:
- LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" formatMaintenance operation of our GitLab server is scheduled for Thursday, October 3rd at 2PM. The server will be unavailable for about 2 hours.
Avoid docker warning:
- LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format