Improve exception handling for fcgi-program socket creation

[0xbad0c0d3]

fixes #1569

[mnaberez]

Description from #1569:

How to reproduce

1. Supervisord must already be started

2. Add such a config:

   [fcgi-program:test]
   command=/bin/true
   socket=tcp://0.0.0.0:8000

3. start a program which listen to the port # socat tcp4-l:8000 stdio

4. # supervisorctl update test

You'll see such an error in the supervisord console

2023-01-27 13:03:20,563 INFO Creating socket tcp://0.0.0.0:8000
2023-01-27 13:03:20,564 ERRO XML-RPC response callback error:Traceback (most recent call last):
  File "/usr/local/lib/python3.10/site-packages/supervisor/xmlrpc.py", line 78, in more
    value = self.callback()
  File "/usr/local/lib/python3.10/site-packages/supervisor/rpcinterface.py", line 947, in allfunc
    callback = func(name, **extra_kwargs)
  File "/usr/local/lib/python3.10/site-packages/supervisor/rpcinterface.py", line 301, in startProcess
    process.spawn()
  File "/usr/local/lib/python3.10/site-packages/supervisor/process.py", line 717, in spawn
    self.before_spawn()
  File "/usr/local/lib/python3.10/site-packages/supervisor/process.py", line 711, in before_spawn
    self.fcgi_sock = self.group.socket_manager.get_socket()
  File "/usr/local/lib/python3.10/site-packages/supervisor/socket_manager.py", line 74, in get_socket
    self.ref_ctr.increment()
  File "/usr/local/lib/python3.10/site-packages/supervisor/socket_manager.py", line 36, in increment
    self.on_non_zero()
  File "/usr/local/lib/python3.10/site-packages/supervisor/socket_manager.py", line 90, in _prepare_socket
    self.socket = self.socket_config.create_and_bind()
  File "/usr/local/lib/python3.10/site-packages/supervisor/datatypes.py", line 210, in create_and_bind
    sock.bind(self.addr())
OSError: [Errno 98] Address in use

as a result supervisord would not even add the program, and no status would be shown