**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
"""Customize permission names for FAB's builtin UserOAuthModelView."""
    class_permission_name = permissions.RESOURCE_MY_PROFILE
    method_permission_name = {
        'userinfo': 'read',
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]
class CustomUserOIDModelView(UserOIDModelView):
    """Customize permission names for FAB's builtin UserOIDModelView."""
    class_permission_name = permissions.RESOURCE_MY_PROFILE
    method_permission_name = {
        'userinfo': 'read',
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]
class CustomUserRemoteUserModelView(UserRemoteUserModelView):
    """Customize permission names for FAB's builtin UserRemoteUserModelView."""
    class_permission_name = permissions.RESOURCE_MY_PROFILE
    method_permission_name = {
        'userinfo': 'read',
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]