404 when selecting an older doc version where the topic did not exist
Description
When selecting an older version of a topic in docs.gitlab.com, the user is presented with a 404 error if the topic did not exist.
Steps to reproduce
- open General LDAP Setup doc page
- select version 12.10
Actual result
Expected result
- A message that the topic could not be located in the selected version.
Further details
Note that the topic may have existed but under a different URL path. For example, a single General LDAP page did not exist in 12.10 because LDAP documentation was split-out for CE and EE.