Per the tracker issue:
> In 3.1 a youtube profilefield was added in which we can insert our youtube
> username to link to it.... There is just one major problem though...
>
> New youtube members no longer get an username. So I think we should decide on
> providing different ways to access their profile.
This PR will allow users to use any valid YouTube-domain URL, which allows for
all 3 formats (`/channel/...`, `/c/...`, and the now-legacy `/user/...`).
Per [YouTube's docs](https://support.google.com/youtube/answer/6180214?hl=en):
> ## Channel URL (ID-based)
> Example: youtube.com/channel/UCUZHFZ9jIKrLroW8LcyJEQQ
>
> This is the standard URL that YouTube channels use.
>
> ...
>
> ## Custom URL
> Example: youtube.com/c/YouTubeCreators
>
> A custom URL is a shorter, easy-to-remember URL that you can share with your
> audience.
>
> ...
>
> ## Legacy username URL
> Example: youtube.com/user/YouTube
>
> Depending on when your channel was created, it may have a username. Usernames
> are no longer required for channels today, but you can still use this URL to
> direct to your channel — even if your channel name has changed since you chose
> your username. Existing usernames can't be changed.
PHPBB3-13859
Wrapping access permissions into <Files "*"> at best has zero effect
and implies unnecessary code and parsing for the web server. At least
it does not block access to files only, but still denies auto indexing
and access to sub directories effectively as well. But removing this
directive is still the cleaner and safer way to deny access to any
kind of resource that is provided within the directory in question.
To deny access to migration data, a single .htaccess file can be used.
This reduces the effort for future changes and it is not required
anymore to create new .htaccess files for every new migration
directory.
Additionally this corrects the fact the "Require" is part of
"mod_authz_core", not "mod_authz_host".
PHPBB3-16556
Signed-off-by: MichaIng <micha@dietpi.com>
