something isn’t handling `.gz`-compressed manpages in the page title properly

Not quite sure if this is the right repo to report this into, but man.voidlinux.org has a small issue where it lists the titles of `.gz`-compressed manpages as being in section “gz”, instead of stripping the `.gz` before looking for the section in the filename.  For example, <https://man.voidlinux.org/steam.6> is titled “steam.6(gz)” when it should be “steam(6)”.