fix(logger): Prevent infinite recursion with log.condition => users or matches

[nickvergessen]

Summary

When we need to check the log condition for a user matches, there is a risk that something on the way checks the log level and would result in an infinite loop.
So we simply check if it's a nested call and use the default warning level in that case.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[nickvergessen]

/backport to stable30

[nickvergessen]

/backport to stable29

[juliusknorr]

Not a blocker:

Seems a bit odd to me to assert for a 503 status on a test that would cover not seeing a "fatal" error, what would the response code otherwise be?

[nickvergessen]

Undefined array key 0 at \/home\/nickv\/Nextcloud\/31\/server\/apps\/dav\/appinfo\/v2\/publicremote.php#81

If I make /public.php/dav/files/foobar so the path matches the regex, it still 503's with "File does not exist" exception which is not handled/translated correctly:

"CustomMessage": "Exception thrown: Sabre\\DAV\\Exception\\NotFound"

But I didn't want to go much deeper (should have a 404 here instead, and I don't want to upload a real file for this simple test)

[nickvergessen]

Translation happens here:

server/apps/dav/lib/Connector/Sabre/PublicAuth.php

Lines 80 to 84 in 3810770

	} catch (\Exception $e) {
	$class = get_class($e);
	$msg = $e->getMessage();
	$this->logger->error($e->getMessage(), ['exception' => $e]);
	throw new ServiceUnavailable("$class: $msg");