Controller object has no attribute advertising times [extended advertisement branch]

When running the bumble `controller.py` of branch `gbg/controller-extended-advertising` I get the following error when connecting to my Zephyr virtual bluetooth device:

```
ERROR:bumble.transport.common:!!! Exception in on_packet: 'Controller' object has no attribute 'advertising_times'
Traceback (most recent call last):
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\transport\common.py", line 152, in feed_data
self.sink.on_packet(bytes(self.packet))
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\controller.py", line 575, in on_packet
self.on_hci_packet(HCI_Packet.from_bytes(packet))
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\controller.py", line 585, in on_hci_packet
self.on_hci_command_packet(packet)
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\controller.py", line 596, in on_hci_command_packet
result = handler(command)
^^^^^^^^^^^^^^^^
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\controller.py", line 1364, in on_hci_le_set_advertising_enable_command
self.schedule_advertiser(self.legacy_advertiser, time.time())
File "C:\Users\user\AppData\Local\Programs\Python\Python311\Lib\site-packages\bumble\controller.py", line 1026, in schedule_advertiser
heapq.heappush(self.advertising_times, (when, advertiser))
^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Controller' object has no attribute 'advertising_times'
```