This option applies to URL redirects when Sub-path handling is set to
Keep sub-paths.
- Keep filename
A request for /old/dir/index.html is redirected with
/dir/index.html appended to the destination.
- Remove filename
A request for /old/dir/index.html is redirected with
/dir/ appended to the destination.
Only a file-like final segment containing a dot, such as index.html,
is removed. Directory-style or extensionless paths are kept as entered.