Get updated config from URL, fallback to local file if download fails.

def get_conf_update(self):
        """
        Get updated config from URL, fallback to local file if download fails.
        """
        dyn_conf = self.get_collection_rules()

        if not dyn_conf:
            return self.get_conf_file()

        version = dyn_conf.get('version', None)
        if version is None:
            raise ValueError("ERROR: Could not find version in json")

        dyn_conf['file'] = self.collection_rules_file
        logger.debug("Success reading config")
        config_hash = hashlib.sha1(json.dumps(dyn_conf).encode('utf-8')).hexdigest()
        logger.debug('sha1 of config: %s', config_hash)
        return dyn_conf