Docker warning: `LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value"`

[deeplow]

Description

Running make build-rpm shows the following warning:

 2 warnings found (use docker --debug to expand):
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 5)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 7)

Steps to Reproduce

Run build-rpm.

Expected Behavior

No warning.

Actual Behavior

Warning shown.

Comments

We just need to follow the suggestion.