code: def _load_controller_settings(self):
          
          try:
              if not os.path.exists(self._config_file):
                  yield from self._import_gns3_gui_conf()
                  self.save()
              with open(self._config_file) as f:
                  data = json.load(f)
          except (OSError, ValueError) as e:
              log.critical("Cannot load %s: %s", self._config_file, str(e))
              self._settings = {}
              return []
  
          if "settings" in data and data["settings"] is not None:
              self._settings = data["settings"]
          else:
              self._settings = {}
          if "gns3vm" in data:
              self.gns3vm.settings = data["gns3vm"]
  
          self.load_appliances()
          return data.get("computes", [])
docs: Reload the controller configuration from disk