When a ConferenceMember is removed from a conference with a
Jitsi-videobridge, an RTCP BYE packet is not always sent. Therefore, if the
ConferenceMember had an associated video SSRC, the stream isn't be
removed until it times out, leaving a blank video container in the interface
for a few seconds.
This works around the problem by removing the
ConferenceMember's ReceiveStream when the ConferenceMember is
removed. The proper solution is to ensure that RTCP BYEs are sent whenever
necessary, and when it is deployed this code should be removed.