People filter is missing from the search

The "people" filter is not longer available on Confluence 5.9 onwards.
There's no such category as "people" even when the custom filter is chosen.

Previously available filter :

Confluence's 5.9 release notes picture shows that it's still available but it's not.
It still exists in Confluence 5.8.16

Users however are still searchable by using :

• "All content" type but it will include all the contents related to him as well.
• Accessing the URL. Replace <USER> and <Confluence URL> accordingly.

  <Confluence URL>/dosearchsite.action?cql=siteSearch~"<USER>"and+type="user"