Remove to set localParticipantMessageListener in joinRoom

this is already done in onAttach which seems to do the job fine after using workManager queues and fixing to set externalSignalingServer to user.
See commits da1714bb and 29a37086

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt

@@ -2003,10 +2003,6 @@ class ChatController(args: Bundle) :
 
                         logConversationInfos("joinRoomWithPassword#onNext")
 
-                        // Ensure that the listener is added if the web socket instance was not set up yet when
-                        // onAttach() was called.
-                        webSocketInstance?.getSignalingMessageReceiver()?.addListener(localParticipantMessageListener)
-
                         if (isFirstMessagesProcessing) {
                             pullChatMessages(false)
                         } else {