Plugins: can't enable video plugin when hosting a conference

Scenario

• Start a video conference
• Enable greenscreen

Current result

• Greenscreen don't start

Expected

• GreenScreen should be started

added media label

added SprintIn progress label

added SprintTo review label and removed SprintIn progress label

added SprintIn progress label

removed SprintIn progress label

https://review.jami.net/c/ring-daemon/+/16912

mentioned in commit cf654cd8

added SprintDone label and removed SprintTo review label

closed

removed SprintDone label