
**Apache Airflow version**:
1.10.13

**What happened**:
`force_logout_after` should be `force_log_out_after` in the code section https://github.com/apache/airflow/blob/master/airflow/settings.py#L372-L381. As `force_log_out_after` is actually used and written in https://github.com/apache/airflow/blob/c5700a56bb3b9a5b872bda0fe0d3de82b0128bdf/UPDATING.md#unify-user-session-lifetime-configuration.

**What you expected to happen**:
`force_logout_after` is renamed to `force_log_out_after`.
airflow/settings.py
import json
import logging
import os
import sys
import warnings
from typing import Optional
import pendulum
from sqlalchemy import create_engine, exc
from sqlalchemy.engine import Engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.orm.session import Session as SASession
from sqlalchemy.pool import NullPool
from airflow.configuration import AIRFLOW_HOME, WEBSERVER_CONFIG, conf  
from airflow.executors import executor_constants
from airflow.logging_config import configure_logging
from airflow.utils.orm_event_handlers import setup_event_handlers
log = logging.getLogger(__name__)
TIMEZONE = pendulum.tz.timezone('UTC')
try:
    tz = conf.get("core", "default_timezone")
    if tz == "system":
        TIMEZONE = pendulum.tz.local_timezone()
    else:
        TIMEZONE = pendulum.tz.timezone(tz)
except Exception:  
    pass
log.info("Configured default timezone %s", TIMEZONE)
HEADER = '\n'.join(
    [
        r'  ____________       _____________',