Fix autoupdater configuration

Bug description

In autoupdater.yml source of centos-7 docker test image is set to "containers/test-images/ubuntu/centos/7" but it should be set to "containers/test-images/centos/7"

Proposal

Just fix this line in autoupdater.yml file.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information