Make sure you have checked _all_ steps below. ### Jira
- [x] My PR addresses the following [Airflow Jira](https://issues.apache.org/jira/browse/AIRFLOW/) issues and references them in the PR title. For example, "\[AIRFLOW-XXX\] My Airflow PR" - https://issues.apache.org/jira/browse/AIRFLOW-3127 - In case you are fixing a typo in the documentation you can prepend your commit with \[AIRFLOW-XXX\], code changes always need a Jira issue. ### Description - [x] Here are some details about my PR, including screenshots of any UI changes: Now in `airflow.cfg`, for Celery-SSL, the item names are "**ssl_active**", "**ssl_key**", "**ssl_cert**", and "**ssl_cacert**" (since PR https://github.com/apache/incubator-airflow/pull/2806/files). But in the documentation https://airflow.incubator.apache.org/security.html?highlight=celery#ssl or https://github.com/apache/incubator-airflow/blob/master/docs/security.rst, it's "**CELERY_SSL_ACTIVE**", "**CELERY_SSL_KEY**", "**CELERY_SSL_CERT**", and "**CELERY_SSL_CACERT**", which is out-dated and may confuse readers. **Screenshot of out-dated doc** <img width="757" alt="screen shot 2018-09-28 at 4 09 18 pm" src="https://user-images.githubusercontent.com/11539188/46196186-e86f6700-c338-11e8-9e86-bca7126c5612.png";> (And fixed a minor typo in `docs/howto/set-config.rst`) [ Full content available at: https://github.com/apache/incubator-airflow/pull/3967 ] This message was relayed via gitbox.apache.org for [email protected]
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