**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
"""Home view."""
        unit_test_mode: bool = conf.getboolean('core', 'UNIT_TEST_MODE')
        if not unit_test_mode and "sqlite" in conf.get("core", "sql_alchemy_conn"):
            db_doc_page = get_docs_url("howto/set-up-database.html")
            flash(
                Markup(
                    "Usage of <b>SQLite</b> detected. It should only be used for dev/testing. "
                    "Do not use <b>SQLite</b> as metadata DB in production. "
                    "We recommend using Postgres or MySQL. "
                    f"<a href='{db_doc_page}'><b>Click here</b></a> for more information."
                ),
                category="warning",
            )
        if not unit_test_mode and conf.get("core", "executor") == "SequentialExecutor":
            exec_doc_page = get_docs_url("executor/index.html")
            flash(