Airflow 2.1.0, Docker

**What happened**:

Users with the Guest role assigned are stuck in a redirect loop once they attempt to login successfully to the web interface.

**What you expected to happen**:

Get minimal access to the dashboard with the appropriate views for a guest role

**How to reproduce it**:
1. Assign a guest role to any user and remove any other roles with the administrator user.
2. Logout from the admin account 
3. Login as the guest user
4. You will notice constant HTTP redirects, and the dashboard will not show up.


tests/www/test_security.py
with pytest.raises(AirflowException) as ctx:
            self.security_manager._sync_dag_view_permissions(
                dag_id='access-control-test',
                access_control={
                    'this-role-does-not-exist': [permissions.ACTION_CAN_EDIT, permissions.ACTION_CAN_READ]
                },
            )
        assert "role does not exist" in str(ctx.value)
    def test_all_dag_access_doesnt_give_non_dag_access(self):
        username = 'dag_access_user'
        role_name = 'dag_access_role'
        with self.app.app_context():
            user = api_connexion_utils.create_user(
                self.app,
                username,
                role_name,
                permissions=[
                    (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
                    (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
                ],
            )
            assert self.security_manager.has_access(
                permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG, user
            )
            assert not self.security_manager.has_access(
                permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE, user
            )
    def test_access_control_with_invalid_permission(self):