Handle socket errors

[K0nne]

Hello,

this PR aims to handle socket errors, which currently produce stacktraces in the plugin output.

before:

Traceback (most recent call last):
  File "/usr/lib64/nagios/plugins/check_http_json.py", line 772, in <module>
    main(sys.argv[1:])
  File "/usr/lib64/nagios/plugins/check_http_json.py", line 727, in main
    json_data = make_request(args, url, context)
  File "/usr/lib64/nagios/plugins/check_http_json.py", line 687, in make_request
    response = urllib.request.urlopen(req, timeout=args.timeout,
  File "/usr/lib64/python3.9/urllib/request.py", line 214, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib64/python3.9/urllib/request.py", line 517, in open
    response = self._open(req, data)
  File "/usr/lib64/python3.9/urllib/request.py", line 534, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
  File "/usr/lib64/python3.9/urllib/request.py", line 494, in _call_chain
    result = func(*args)
  File "/usr/lib64/python3.9/urllib/request.py", line 1389, in https_open
    return self.do_open(http.client.HTTPSConnection, req,
  File "/usr/lib64/python3.9/urllib/request.py", line 1350, in do_open
    r = h.getresponse()
  File "/usr/lib64/python3.9/http/client.py", line 1377, in getresponse
    response.begin()
  File "/usr/lib64/python3.9/http/client.py", line 320, in begin
    version, status, reason = self._read_status()
  File "/usr/lib64/python3.9/http/client.py", line 281, in _read_status
    line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
  File "/usr/lib64/python3.9/socket.py", line 716, in readinto
    return self._sock.recv_into(b)
  File "/usr/lib64/python3.9/ssl.py", line 1277, in recv_into
    return self.read(nbytes, buffer)
  File "/usr/lib64/python3.9/ssl.py", line 1135, in read
    return self._sslobj.read(len, buffer)
socket.timeout: The read operation timed out

after:

UNKNOWN: Status UNKNOWN. Socket timeout after 10s | https://<target_url>