python-swiftclient should retry at least *some* SSLErrors

Currently, our retry logic special-cases SSLErrors to fail quickly: https://github.com/openstack/python-swiftclient/blob/4.2.0/swiftclient/client.py#L1801-L1802

Presumably we did this because if we get back an error about certificate verification (cert expired, cert self-signed), there's no point in retrying -- we expect the same result. However, there are other sorts of errors that might come up; for example,

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 699, in urlopen
    httplib_response = self._make_request(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 382, in _make_request
    self._validate_conn(conn)
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 1012, in _validate_conn
    conn.connect()
  File "/usr/lib/python3/dist-packages/urllib3/connection.py", line 411, in connect
    self.sock = ssl_wrap_socket(
  File "/usr/lib/python3/dist-packages/urllib3/util/ssl_.py", line 449, in ssl_wrap_socket
    ssl_sock = _ssl_wrap_socket_impl(
  File "/usr/lib/python3/dist-packages/urllib3/util/ssl_.py", line 493, in _ssl_wrap_socket_impl
    return ssl_context.wrap_socket(sock, server_hostname=server_hostname)
  File "/usr/lib/python3.10/ssl.py", line 513, in wrap_socket
    return self.sslsocket_class._create(
  File "/usr/lib/python3.10/ssl.py", line 1071, in _create
    self.do_handshake()
  File "/usr/lib/python3.10/ssl.py", line 1342, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLZeroReturnError: TLS/SSL connection has been closed (EOF) (_ssl.c:997)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 755, in urlopen
    retries = retries.increment(
  File "/usr/lib/python3/dist-packages/urllib3/util/retry.py", line 574, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='...', port=443): Max retries exceeded with url: ... (Caused by SSLError(SSLZeroReturnError(6, 'TLS/SSL connection has been closed (EOF) (_ssl.c:997)')))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/swiftclient/service.py", line 1209, in _download_object_job
    headers, body = conn.get_object(container, obj, **get_args)
  File "/usr/lib/python3/dist-packages/swiftclient/client.py", line 1970, in get_object
    rheaders, body = self._retry(None, get_object, container, obj,
  File "/usr/lib/python3/dist-packages/swiftclient/client.py", line 1856, in _retry
    rv = func(self.url, self.token, *args,
  File "/usr/lib/python3/dist-packages/swiftclient/client.py", line 1306, in get_object
    conn.request(method, path, '', headers)
  File "/usr/lib/python3/dist-packages/swiftclient/client.py", line 470, in request
    self.resp = self._request(method, url, headers=headers, data=data,
  File "/usr/lib/python3/dist-packages/swiftclient/client.py", line 454, in _request
    return self.request_session.request(*arg, **kwarg)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 514, in send
    raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='...', port=443): Max retries exceeded with url: ... (Caused by SSLError(SSLZeroReturnError(6, 'TLS/SSL connection has been closed (EOF) (_ssl.c:997)')))

Note that this is a particularly disingenuous error message: despite saying "Max retries exceeded" and using our default --retries=5, not one attempt has been made to retry!