**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
"""Set task instance state."""
        try:
            count = len(tis)
            for ti in tis:
                ti.set_state(target_state, session)
            session.commit()
            flash(f"{count} task instances were set to '{target_state}'")
        except Exception:
            flash('Failed to set state', 'error')
    @action('set_running', "Set state to 'running'", '', single=False)
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
        ]
    )
    def action_set_running(self, tis):
        """Set state to 'running'"""
        self.set_task_instance_state(tis, State.RUNNING)
        self.update_redirect()
        return redirect(self.get_redirect())
    @action('set_failed', "Set state to 'failed'", '', single=False)
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
        ]
    )
    def action_set_failed(self, tis):