Fixed logging out, added a proper function to list sessions

By fixing logging out, other request probably got fixed as well,
since now we can also read MessagesAcknowledge requests

telethon/network/mtproto_sender.py

@@ -192,6 +192,16 @@ class MtProtoSender:
         if code == 0xa7eff811:  # bad_msg_notification
             return self.handle_bad_msg_notification(msg_id, sequence, reader)
 
+        if code == 0x62d6b459:  # msgs_ack, it may handle the request we wanted
+            ack = reader.tgread_object()
+            for message_id in ack.msg_ids:
+                if message_id in self.need_confirmation:
+                    self.need_confirmation.remove(message_id)
+
+            if request and request.msg_id in ack.msg_ids:
+                request.confirm_received = True
+            return False
+
         # If the code is not parsed manually, then it was parsed by the code generator!
         # In this case, we will simply treat the incoming TLObject as an Update,
         # if we can first find a matching TLObject