- get users in voice conference when meeting is started

...ebutton/red5/monitoring/BbbAppsIsAliveMonitorService.java

...java/org/bigbluebutton/web/services/KeepAliveService.java

.../src/main/scala/org/bigbluebutton/core/MeetingActor.scala

...c/main/scala/org/bigbluebutton/core/api/OutMessages.scala

...button/core/pubsub/senders/UsersEventRedisPublisher.scala

...igbluebutton/endpoint/redis/KeepAliveRedisPublisher.scala