Regression from #3954

[Cornelicorn]

I found a regression with #3954. When using a unix domain socket via a URL scheme (specifcially unix:///run/redis/redis.sock?db=0), there is an excpetion raised, since there is no port for unix socket connections.

   File "/opt/netbox/venv/lib/python3.13/site-packages/redis/commands/core.py", line 2069, in get
     return self.execute_command("GET", name, keys=[name])
            ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/opt/netbox/venv/lib/python3.13/site-packages/redis/client.py", line 716, in execute_command
     return self._execute_command(*args, **options)
            ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
   File "/opt/netbox/venv/lib/python3.13/site-packages/redis/client.py", line 755, in _execute_command
     server_port=conn.port,
                 ^^^^^^^^^
 AttributeError: 'UnixDomainSocketConnection' object has no attribute 'port'

This was discovered when using django-redis for caching in netbox.
Downgrading to 7.1.1 solves this issue.