Containers not found after inginious docker-agent update

After having updated my inginious instance last week, all codings problems where crashing because of "unavailable environment".
After some research, I believe this is related to the commit on INGInious issue #435 [UCL-INGI/INGInious/pull/435] : The label org.inginious.grading.agent_version is missing on the INGInious-containers and so they are not recognised by the inginious docker-agent anymore.

Manually adding the label to the dockerfile of my grading environment solved the issue in my case, but it would be nice to update the official docker images accordingly.