Bug in visitor implementation

[ForNeVeR]

06:06:49.415 [CodingteamSystem-akka.actor.default-dispatcher-6933] WARN  r.o.c.h.p.jabber.MucMessageHandler - Cannot find participant [email protected]/ForNeVeR in the participant list
06:06:49.421 [CodingteamSystem-akka.actor.default-dispatcher-6944] ERROR akka.actor.OneForOneStrategy - (Actor[akka://CodingteamSystem/user/core/$d#1119203458],CommandDefinition(RoomAdminAccess,visitors,ru.org.codingteam.horta.plugins.visitor.VisitorsCommand$@1d6ec9c3)) (of class scala.Tuple2)
scala.MatchError: (Actor[akka://CodingteamSystem/user/core/$d#1119203458],CommandDefinition(RoomAdminAccess,visitors,ru.org.codingteam.horta.plugins.visitor.VisitorsCommand$@1d6ec9c3)) (of class scala.Tuple2)
        at ru.org.codingteam.horta.core.Core$$anonfun$executeCommand$1.apply(Core.scala:195) ~[horta-hell.jar:0.11]
        at ru.org.codingteam.horta.core.Core$$anonfun$executeCommand$1.apply(Core.scala:195) ~[horta-hell.jar:0.11]
        at scala.collection.immutable.List.foreach(List.scala:381) ~[horta-hell.jar:0.11]
        at ru.org.codingteam.horta.core.Core.executeCommand(Core.scala:195) ~[horta-hell.jar:0.11]
        at ru.org.codingteam.horta.core.Core.ru$org$codingteam$horta$core$Core$$processMessage(Core.scala:133) ~[horta-hell.jar:0.11]
        at ru.org.codingteam.horta.core.Core$$anonfun$receive$1.applyOrElse(Core.scala:94) ~[horta-hell.jar:0.11]
        at akka.actor.Actor$class.aroundReceive(Actor.scala:465) ~[horta-hell.jar:0.11]
        at ru.org.codingteam.horta.core.Core.aroundReceive(Core.scala:31) ~[horta-hell.jar:0.11]
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) [horta-hell.jar:0.11]
        at akka.actor.ActorCell.invoke(ActorCell.scala:487) [horta-hell.jar:0.11]
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) [horta-hell.jar:0.11]
        at akka.dispatch.Mailbox.run(Mailbox.scala:220) [horta-hell.jar:0.11]
        at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) [horta-hell.jar:0.11]
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [horta-hell.jar:0.11]
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [horta-hell.jar:0.11]
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [horta-hell.jar:0.11]
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [horta-hell.jar:0.11]