SQLAlchemy engine configuration is not passed to FAB based UI. Faced this issue when running Airflow with MySQL metadata store with wait_timeout = 120. Webserver is failing with Internal Server Error due to "[MySQL Server has gone away](https://docs.sqlalchemy.org/en/13/faq/connections.html#mysql-server-has-gone-away)" error. Settings like `sql_alchemy_pool_recycle` and  `sql_alchemy_pool_pre_ping` have no impact on FAB internal communication with MySQL.

**Apache Airflow version**: 1.10.12
airflow/settings.py
"""
    This setting allows altering ``kubernetes.client.models.V1Pod`` object
    before they are passed to the Kubernetes client by the ``PodLauncher``
    for scheduling.
    To define a pod mutation hook, add a ``airflow_local_settings`` module
    to your PYTHONPATH that defines this ``pod_mutation_hook`` function.
    It receives a ``Pod`` object and can alter it where needed.
    This could be used, for instance, to add sidecar or init containers
    to every worker pod launched by KubernetesExecutor or KubernetesPodOperator.
    """
def configure_vars():
    """Configure Global Variables from airflow.cfg"""
    global SQL_ALCHEMY_CONN
    global DAGS_FOLDER
    global PLUGINS_FOLDER
    SQL_ALCHEMY_CONN = conf.get('core', 'SQL_ALCHEMY_CONN')
    DAGS_FOLDER = os.path.expanduser(conf.get('core', 'DAGS_FOLDER'))
    PLUGINS_FOLDER = conf.get(
        'core',
        'plugins_folder',
        fallback=os.path.join(AIRFLOW_HOME, 'plugins')
    )
def configure_orm(disable_connection_pool=False):