Unresponsive join/leave circle since introduction of `'/joinable/'`

Since changing the circle admin to work on 'circles/joinable/' our workaround for framework/sib-core#524 (closed) to make join/leave buttons reactive isn't working

assigned to @jbpasquier and unassigned @calummackervoy

mentioned in merge request !118 (closed)

Closing in favor of sib-core#524

closed