fatbuildrctl crash on JSONDecodeError when server does not respond JSON

[rezib]

fatbuildrctl crashes with JSONDecodeError when HTTP server does not respond with valid JSON:

$ fatbuildrctl --uri https://build.rackslab.io/devs build -a slurm-web -d bookworm --sources 3.0.0a1.dev1@. --watch
Generating artifact slurm-web source tarball version 3.0.0a1.dev23 using directory .
Traceback (most recent call last):
  File "/usr/bin/fatbuildrctl", line 33, in <module>
    sys.exit(load_entry_point('Fatbuildr==2.1.0.dev57', 'console_scripts', 'fatbuildrctl')())
  File "/usr/lib/python3/dist-packages/fatbuildr/cli/__init__.py", line 34, in run
    cls()
  File "/usr/lib/python3/dist-packages/fatbuildr/cli/fatbuildrctl.py", line 437, in __init__
    args.func(args)
  File "/usr/lib/python3/dist-packages/fatbuildr/cli/fatbuildrctl.py", line 1000, in _run_build
    self._submit_watch(
  File "/usr/lib/python3/dist-packages/fatbuildr/cli/fatbuildrctl.py", line 1068, in _submit_watch
    task_id = caller(*args)
  File "/usr/lib/python3/dist-packages/fatbuildr/protocols/http/client.py", line 38, in error_handler_wrapper
    return method(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/fatbuildr/protocols/http/client.py", line 182, in build
    return response.json()['task']
  File "/usr/lib/python3/dist-packages/requests/models.py", line 900, in json
    return complexjson.loads(self.text, **kwargs)
  File "/usr/lib/python3/dist-packages/simplejson/__init__.py", line 525, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 370, in decode
    obj, end = self.raw_decode(s)
  File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 400, in raw_decode
    return self.scan_once(s, idx=_w(s, idx).end())
simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

This case should be handled more nicely.