**Apache Airflow version**: 2.1.0

**Browsers**: Chrome and Firefox

**What happened**:

Before upgrading to 2.1.0

![before](https://user-images.githubusercontent.com/14293802/120359517-c1ca1100-c2d5-11eb-95ba-58ccc0a3ac37.png)

After upgrading to 2.1.0

![after](https://user-images.githubusercontent.com/14293802/120359528-c4c50180-c2d5-11eb-8e04-f34846ea2736.png)

**What you expected to happen**:

Show/Edit/Delete under Security -> Users are available

<!-- What do you think went wrong? -->

**How to reproduce it**:

Go to Security -> Users (as an admin of course) 
airflow/www/views.py
only_failed=only_failed,
        )
    @expose('/dagrun_clear', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_DELETE, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def dagrun_clear(self):
        """Clears the DagRun"""
        dag_id = request.form.get('dag_id')
        origin = get_safe_url(request.form.get('origin'))
        execution_date = request.form.get('execution_date')
        confirmed = request.form.get('confirmed') == "true"
        dag = current_app.dag_bag.get_dag(dag_id)
        execution_date = timezone.parse(execution_date)
        start_date = execution_date
        end_date = execution_date
        return self._clear_dag_tis(dag, start_date, end_date, origin, recursive=True, confirmed=confirmed)
    @expose('/blocked', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def blocked(self, session=None):