Error in periodic_update function

[lourencor]

Describe the bug
So, this started happening yesterday while in the middle of trying to sell RNDR.

Couldn't figure out why since there is not update on the bot, and no parsing error that I can detect on version.json

Error Log

Traceback (most recent call last):
  File "/home/ubuntu/trading_bots/trading-bot-new-coins/bot/bot.py", line 57, in run_async
    self.periodic_update()
  File "/home/ubuntu/trading_bots/trading-bot-new-coins/bot/bot.py", line 159, in periodic_update
    self.upgrade_update()
  File "/home/ubuntu/trading_bots/trading-bot-new-coins/bot/bot.py", line 139, in upgrade_update
    self.config.check_version()
  File "/home/ubuntu/trading_bots/trading-bot-new-coins/util/config.py", line 125, in check_version
    latest_versions = json.loads(requests.get(self.VERSION_URL).text)
  File "/usr/lib/python3.8/json/__init__.py", line 357, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.8/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.8/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 2 column 1 (char 1)

[cdalton713]

This may have been a network issue, I'll add exception handling to skip over this check if parsing fails.