Provide better error message if settings.yml cannot be loaded

import searx.settings_loader

from os import environ

from os.path import realpath, dirname, join, abspath, isfile

from sys import exit

from searx.exceptions import SearxSettingsException

searx_dir = abspath(dirname(__file__))

engine_dir = dirname(realpath(__file__))

static_path = abspath(join(dirname(__file__), 'static'))

settings, settings_outgoing = {}, ''

try:

    settings, settings_load_message = searx.settings_loader.load_settings()

except SearxSettingsException as e:

    logger = logging.getLogger('searx')

    logger.error('Failed to load settings file: {}'.format(str(e)))

    exit(1)

if settings['ui']['static_path']:

    static_path = settings['ui']['static_path']

def load_settings(load_user_setttings=True):

    default_settings_path = get_default_settings_path()

    user_settings_path = get_user_settings_path()

    if user_settings_path is None or not load_user_setttings:

    # no user settings

    if user_settings_path is None or not load_user_setttings:

        if default_settings_path is None:

            raise SearxSettingsException(

                'missing default settings.yml file and there is no user configured file.\n'

                'Please create a configuration file and put it under the root of searx or in /etc/searx or'

                'configure the path in SEARX_SETTINGS_PATH.',

                None,

            )

        return (load_yaml(default_settings_path),

                'load the default settings from {}'.format(default_settings_path))