Python apprise problem with MQTT notifications

[jds11111]

Describe the bug
MQTT notifications fail

To Reproduce
Steps to reproduce the behavior:

1. Goto Settings -> Tools. Set up MQTT notification
2. Test it.
3. View error: ERROR - Could not load MQTT Notification URL: mqtt://hassio:g...l@1...1:1883/birdnet/sightings
4. Run apprise in CLI:

birdnetpi:~/BirdNET-Pi/birdnet/bin$ ./apprise -vvv -b 'test' "mqtt://username:password@192.168.1.91:1883/birdnet/sightings"
2024-02-19 08:36:08,619 - DEBUG - Language set to en
2024-02-19 08:36:09,099 - DEBUG - Notification Plugin 101(s) and 142 Schema(s) loaded in 0.4715s
Exception ignored in: <function Client.__del__ at 0x7f9614dca0>
Traceback (most recent call last):
  File "/home/pi/BirdNET-Pi/birdnet/lib/python3.9/site-packages/paho/mqtt/client.py", line 874, in __del__
    self._reset_sockets()
  File "/home/pi/BirdNET-Pi/birdnet/lib/python3.9/site-packages/paho/mqtt/client.py", line 1133, in _reset_sockets
    self._sock_close()
  File "/home/pi/BirdNET-Pi/birdnet/lib/python3.9/site-packages/paho/mqtt/client.py", line 1119, in _sock_close
    if not self._sock:
AttributeError: 'Client' object has no attribute '_sock'
2024-02-19 08:36:09,106 - ERROR - Could not load MQTT Notification URL: mqtt://username:password@1...1:1883/birdnet/sightings
2024-02-19 08:36:09,107 - ERROR - There are no service(s) to notify

Additional context
I had the same problem with the previous fork, but couldn't fix it there, either (https://github.com/mcguirepr89/BirdNET-Pi/discussions/321#discussioncomment-8431278)

Your build
Running on RPi4B, latest build. MIgrated over from previous fork (which worked extremely well using the documentation.) I suspect that it is a python version/library problem. This reminds me why I moved many things over to containers because of python problems like this. It is probably not a bug with this software, but hope somebody could point me in the right direction.