- flag the user first when receiving user left event in case user is just reconnecting

...g/bigbluebutton/core/apps/users/UserLeaveReqMsgHdlr.scala

...rc/main/scala/org/bigbluebutton/core/models/Users2x.scala

...scala/org/bigbluebutton/core/running/HandlerHelpers.scala

...n/scala/org/bigbluebutton/core/running/MeetingActor.scala

...scala/org/bigbluebutton/core2/testdata/FakeTestData.scala