fix "funToCallWhenLeaveSuccess" (leftover after solving merge conflicts)

invoking funToCallWhenLeaveSuccess went to viewModel, now named as functionToCallAfterLeave

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

Author: mahibi

app/src/main/java/com/nextcloud/talk/chat/ChatActivity.kt

@@ -449,11 +449,6 @@ class ChatActivity :
                 }
 
                 sessionIdAfterRoomJoined = "0"
-
-                if (state.funToCallWhenLeaveSuccessful != null) {
-                    Log.d(TAG, "a callback action was set and is now executed because room was left successfully")
-                    state.funToCallWhenLeaveSuccessful.invoke()
-                }
             }
 
             else -> {}